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Abstract

This study investigated the effects of different progressive lenses and a single-vision lens on eye, head, and putter motions during the golf putting stroke in presbyopes. Six subjects ranging in age from 49 to 69 years, with golf experience ranging from modest to high, participated in the study. Three lens conditions were tested: single-vision distance lenses (SV), newer "soft" design (PAL1), and older "hard" design (PAL2) progressive lenses. The two progressive lenses have different intermediate zone widths. For each condition, the subject completed 15 putts to a standard size golf-hole target 9 feet away. Eye, head, and putter movements were recorded. The data were analyzed over the interval from the beginning of the putting stroke to the moment of ball impact. The root mean square (RMS) of the eye, head, and putter movements within this time interval were calculated for each record, and the data were averaged across subjects. Putting accuracy was also monitored. The results showed that the mean RMS values of the eye movements were not significantly different among the three conditions, although it was slightly smaller for the PAL2 condition. The mean head movement RMS values were not significantly different between the SV and PAL1 conditions, whereas it was significantly higher for the PAL2 than the PAL1 condition. In addition, putt amplitude, duration, and accuracy were not significantly different among the three conditions. There were no obvious differences between experienced and inexperienced golfers. For the PAL2 condition, the larger head movements observed (and the corresponding smaller eye movement variation) may be due to its smaller intermediate zone width. Progressive addition lens users have been previously observed to remain well within the boundaries of the intermediate zone of clarity, possibly by adopting a conservative eye movement strategy, and therefore are forced to compensate with larger head movements. The results provide new and useful guidelines for the future design of progressive lenses to improve their performance during outdoor activities such as golf.
EFFECT OF WEARING
SINGLE-VISION &
PROGRESSIVE LENSES
ON
EYE &HEAD MOVEMENTS
DURING THE
GOLF PUTTING STROKE
n
George K. Hung, Ph.D.
a
n
Kenneth J. Ciuffreda O.D.,
Ph.D.
b
n Arkady Selenow O.D.
c
n George A. Zikos O.D., M.S.
c
a. Dept. of Biomedical Engineering, Rutgers
University, Piscataway, NJ
b. Dept. of Vision Sciences, State University of
New York, State College of Optometry, New
York, NY
c. Manhattan Vision Associates/Institute of Vi-
sion Research, New York, NY
Abstract
This study investigated the effects of differ
-
ent progressive lenses and a single-vision
lens on eye, head, and putter motions dur
-
ing the golf putting stroke in presbyopes.
Six subjects ranging in age from 49 to 69
years, with golf experience ranging from
modest to high, participated in the study.
Three lens conditions were tested: sin
-
gle-vision distance lenses (SV), newer
“soft” design (PAL1), and older “hard” de
-
sign (PAL2) progressive lenses. The two
progressive lenses have different interme
-
diate zone widths. For each condition, the
subject completed 15 putts to a standard
size golf-hole target 9 feet away. Eye, head,
and putter movements were recorded. The
data were analyzed over the interval from
the beginning of the putting stroke to the
moment of ball impact. The root mean
square (RMS) of the eye, head, and putter
movements within this time interval were
calculated for each record, and the data
were averaged across subjects. Putting ac
-
curacy was also monitored. The results
showed that the mean RMS values of the eye
movements were not significantly different
among the three conditions, although it was
slightly smaller for the PAL2 condition.
The mean head movement RMS values were
not significantly different between the SV
and PAL1 conditions, whereas it was sig-
nificantly higher for the PAL2 than the
PAL1 condition. In addition, putt ampli-
tude, duration, and accuracy were not sig-
nificantly different among the three
conditions. There were no obvious differ
-
ences between experienced and inexperi
-
enced golfers. For the PAL2 condition, the
larger head movements observed (and the
corresponding smaller eye movement vari
-
ation) may be due to its smaller intermedi
-
ate zone width. Progressive addition lens
users have been previously observed to re
-
main well within the boundaries of the in
-
termediate zone of clarity, possibly by
adopting a conservative eye movement
strategy, and therefore are forced to com
-
pensate with larger head movements. The
results provide new and useful guidelines
for the future design of progressive lenses
to improve their performance during out
-
door activities such as golf.
Key Words
eye movements, golf putting movements,
head movements, presbyopia, progressive
addition lenses, putting accuracy, single vi
-
sion lenses, wireless sensor system
INTRODUCTION
S
ports science and sports medi-
cine are becoming a popular
means of addressing specific
questions posed by athletes and their
trainers concerning the body’s forces and
actions during athletic motions. It has, for
example, provided valuable information
about the golf swing and physical forces
impacting on the golf ball.
1,2
Much of this
information has been obtained using
high-speed photography and video sys
-
tems spanning almost a century.
3-7
In
-
deed, the components of the golf swing
have been studied in great detail over the
past 50 years. However, there is a surpris
-
ing lack of objective simultaneous mea
-
surements of eye and head motion during
the golf swing, especially for putting.
8
Putting is a crucial element in golf.
9-11
This is demonstrated by statistics com
-
piled by the Professional Golfers Associa
-
tion, which showed that the best players in
the world expend approximately 40% of
their total strokes in a round on putting.
12
Professional golf instructors and sports
psychologists have stressed the impor
-
tance of minimal or no eye and head
movements throughout the putting stroke.
The eyes are important because they pro
-
vide accurate perception of the distance
and direction to the target hole location to
result in successful execution of a putting
stroke. If the eyes are fixated elsewhere at
a position other than the ball, this can lead
Journal of Behavioral Optometry Volume 17/2006/Number 5/Page 115
to an improper stroke and a missed putt.
Head position is also important because it
allows for maintenance of a stable visual
environment. Head movement during the
stroke can lead to misalignment and a
missed putt.
With the increased number of baby
boomers playing golf, progressive addi
-
tion lenses (PALs) have become an impor
-
tant component of golf activities. As one
ages, the accommodative response de
-
creases, and beyond the age of about 50
years, the crystalline lens acts essentially
as a fixed-focus optical system.
13,14
The
PAL can remedy this by providing a
means to see clearly as a continuum at far,
intermediate, and near distances. Thus,
during a round of golf, the PAL allows the
player to see the ball at address, midflight,
and at a far distance where the ball lands.
The need for clear vision through the PAL
is particularly important during putting,
since viewing through different portions
of the PAL can affect target clarity and
awareness of surround during the execu-
tion of the putting stroke.
Different PAL designs provide differ-
ent attributes. The older “hard” design
lenses have an abrupt and narrow inter-
mediate zone, which may induce more
head movements for accurate visualiza-
tion.
15-17
On the other hand, the newer
“soft” design lenses have a less abrupt and
wider intermediate zone that provide a
larger field of view, thus requiring less eye
and head movements for viewing a
scene.
15-17
These attributes may have dif
-
ferent effects on vision function during
physical activities such as golf. This study
investigated the differences in eye and
head movements of golfers during the
putting stroke while wearing single-vision
(SV), newer “soft” design (PAL1), and
older “hard” design (PAL2) progressive
lenses.
METHOD
Apparatus
A wireless sensor system was custom-
designed by the first author. It allowed for
simultaneous recording of eye, head, and
putter motions during the golf putting
stroke (Figures 1 and 2). Head movements
were measured using an accelerometer
placed in a small circuit board, which was
mounted on the beak of a visor.
18-20
The
eye sensor consisted of infrared emit
-
ter-detector pairs that were aimed at the
horizontal limbal boundaries of the eye,
where the reflectance is directly related to
horizontal eye position. A flexible wire
and adjustable plastic assembly were an
-
chored on the side of the visor to position
the eye sensor at a fixed distance in front
of the left eye. This assembly configura
-
tion provided for full adjustment of sensor
position in different users. In addition,
putter motion was measured using an ac-
celerometer placed in a circuit board
which was mounted on the shaft of the
putter. The two circuit boards on the visor
and the putter shaft contain antennas that
send the head, eye, and putter signals to a
receiving board, which is plugged directly
into the USB port of the PC for serial data
transmission.
Subjects and Procedure
Four male and two female subjects,
ranging in age from 49 to 69 years, partici
-
pated in the study. Two of the male sub
-
jects were experienced in playing golf,
whereas the others were novices.
Three lens conditions were used:
1. Single vision CR-39 lens spectacles
prescribed according to the subject’s
distant vision correction.
2. PAL 1, which is a “soft” newer design
with a 3.9mm(wide) intermediate
zone.
3. PAL 2, which is a “harder” older de
-
sign with a 2.3mm intermediate zone.
Both PAL designs incorporated the sub
-
ject’s present prescription. The wider in
-
termediate zone (PAL1) lens has less
unwanted astigmatism in the periphery,
while the narrower intermediate zone
(PAL2) lens has more unwanted astigma
-
tism in the periphery. None of the subjects
were adapted to any one of the lens styles,
nor were they given any specific instruc
-
tion on how to use the lenses.
The sequence of spectacle lenses
tested was randomized among the sub
-
jects. For each condition, the subject com
-
pleted 15 putts to a standard size golf-hole
target 9 feet away on a smooth artificial
grass environment. Eye, head, and putter
movements were recorded over 3-sec in
-
tervals at a 64 Hz sampling rate using the
wireless sensor system (see Figure 3).
Data Analysis
The data were analyzed using pro
-
grams written in C++
a
and MATLAB
b
codes. The results were displayed in three
channels as position time courses for put
-
ter, eye, and head movements. Also dis
-
played were the corresponding velocity
traces. For each record, the beginning of
the putt (i.e., the take-away), as well as the
Volume 17/2006/Number 5/Page 116 Journal of Behavioral Optometry
Figure 1. Visor with head sensor (attached to
beak of visor) and eye sensor (below the visor).
Figure 2. Subject wearing spectacle lenses and
visor with attached head and eye sensors.
Figure 3. Subject putting while wearing recording
system containing eye, head, and putting motion
sensors.
end of the putt (i.e., return to the point of
impact), were marked visually on the PC
screen. The program calculated the RMS
of eye and head movements, as well as the
duration and amplitude of the putt, over
the marked time interval.
The data from each subject were aver
-
aged, and the averaged data for the six
subjects were used in the statistical analy
-
sis. One-tailed t-tests (MATLAB
b
Statisti
-
cal Analysis Toolbox) were performed to
assess the statistical significance of differ
-
ences between the progressive and SV add
lenses for the various parameters: RMS of
eye and head movements, putt amplitude,
putt duration, and the percentage of putts
made.
RESULTS
Typical records during the putting
stroke are shown for small (Figure 4a) and
large (Figure 4b) amounts of eye and head
movements before ball impact. The data
were converted to equivalent linear dis
-
placement (in cm) on the putting surface.
The mean RMS values of the eye
movements were not significantly differ
-
ent among the three conditions, although
it was slightly smaller for the PAL2 condi
-
tion. The mean head movement RMS val
-
ues were not significantly different
between the SV and PAL1 conditions,
whereas they were significantly higher for
the PAL2 versus the PAL1 condition
(t-test, p < 0.05). In addition, putt ampli
-
tude, duration, and percentage made were
not significantly different among the three
conditions (see Table 1). There were no
obvious differences between the experi
-
enced and inexperienced golfers.
DISCUSSION
Among many other factors, there are
two physical factors that may lead to
missed putts. Putting on a smooth artifi
-
cial surface does not necessarily mean a
perfectly flat surface. There may be grain
and slight contour variations even for an
Journal of Behavioral Optometry Volume 17/2006/Number 5/Page 117
Figure 4a. Record showing relatively small eye and head movements before ball impact at 1.5 sec
(vertical dashed lines) with PAL2 lens. Upwards on plot is towards the hole. Putter position is estimated
from acceleration data, and is used primarily to determine the point of impact.
Figure.4b. Record showing relatively large and variable eye and head movements before ball impact at
about 1.5 sec (vertical dashed lines) with PAL1 lens.
Table 1. Average Values (n=6)
SV PAL1 PAL2
Eye (rms, cm) 6.23 6.77 5.37
Head (rms, cm) 4.70 4.64* 5.95*
Putt amplitude
(cm)
34.5 36.3 36.2
Putt Duration
(sec)
0.86 0.90 0.90
Putt (% made) 54.0 39.6 42.8
* = p<0.05
apparently straight putt, similar to actual
greens that appear to be flat. Nevertheless,
the subjects were given a few trial putts
prior to the experiments, and this in part
allowed them to compensate for any
“break” (i.e., a specific golf term referring
to the expected turn of the ball due to the
contour or grain) on the artificial surface.
Also, the PAL lenses may contribute in
part to a misreading of the true position of
the target due to the prismatic effect
through the periphery of the lens. Thus, to
accurately assess alignment of the putt,
the subject should look at the golf hole
through the central portion of the PAL
lens by turning the head fully rather than
partially, as is normally done with single
vision lenses.
The amount of accommodation
needed for the putts was calculated to
range from 0.68 to 0.77 D, which corre
-
sponds to a range of distances from the eye
to the ball from 148 cm to 131 cm. If the
subject viewed through the central dis
-
tance-refraction portion of the PAL lens,
and accounting for a depth of focus of
about ±0.25 D,
21,22
this would leave about
0.5 D of accommodative stimulus. Thus,
there would be a small amount of blur ex-
cept for the younger presbyopes, who may
be able to accommodate for the remaining
dioptric stimulus. However, all of these
presbyopic subjects should be able to see
the ball clearly by a slight upward tilt of
the head to look through a particular por-
tion of the progressive add lens that just
compensates for the optical power of the
target. But this may not be the most com
-
fortable position, so subjects may com
-
promise by reducing the amount of head
tilt to achieve a reasonably comfortable
posture while permitting a small amount
of defocus blur.
The results of the present investigation
demonstrated clear but subtle differences
in eye and head movements during golf
putting with the three lenses. For the PAL2
lens, which has the most restricted clear
field-of-view, head movement variation
was significantly greater, while eye move
-
ment variation was smaller than with the
PAL1 lens. Regardless of the type of lens,
head and/or eye movements are undesir
-
able during golf putting, as golf-teaching
professionals stress in their lessons.
9
Pre
-
sumably, the presence of such movements
would impact adversely on putting accu
-
racy. While putting accuracy was not sig
-
nificantly different for the three lenses, it
was about 10% better with the SV versus
either PAL lens. Perhaps this finding was
not statistically significant due to the rela
-
tively small sample size. An expanded
study with a larger sample size may deter
-
mine whether it is indeed statistically sig
-
nificant, and is so, this percentage
difference could have important perfor
-
mance and thus lens design consequences.
The present findings are consistent
with earlier studies in our laboratory with
PAL lenses, but involving various near vi
-
sion reading tasks.
15-17
In those studies, as
the PAL intermediate zone became nar
-
rower and restricted the clear field-of-
view, both eye and head movement ampli
-
tudes increased, as well as the time to at
-
tain fixational stability after a saccade.
Other dynamic aspects of eye and head
movements, such as peak velocity, were
not affected and remained normal.
The present findings may also provide
important information with respect to fu
-
ture PAL design. The greater the clear
field-of-view, presumably the more accu-
rate and time-optimal is one’s sensori-
motor performance.
23
Although one op-
tion would be to wear SV lenses designed
to have a wide and clear field-of-view for
putting only at an intermediate distance, it
would be less cumbersome and problem-
atic to have a lens that was satisfactory at
all golf distances, which would include a
range from far (i.e., several hundred
yards) to intermediate (i.e., the eye to ball
distance during putting) distances. Fur
-
thermore, the same PAL could be used for
the relatively infrequent near tasks at 40
cm or so, such as reading the scorecard.
Thus, a multi-function PAL spectacle lens
designed specifically for golfing and re
-
lated tasks would be of great benefit to the
serious golfer who is striving to obtain op
-
timal conditions for maximum perfor
-
mance. If such a lens were available, it
could reduce or eliminate the presence of
undesirable astigmatism and distortion
outside this zone, which create defocus
and prismatic displacement effects. These
factors might affect the determination of
the “line” based on judgment of the cup’s
absolute distance and direction through
this peripheral region. Thus, the improved
PAL lens could reduce the visual/
proprioceptive mismatch that would oth
-
erwise be present, thus leading to im
-
proved perception of these critical target
location parameters.
CONCLUSION
This study quantified the effects of
single-vision and progressive lenses on
eye, head, and putter motions during the
golf putting stroke. The wireless device
provided a convenient means to measure
these different factors simultaneously
without subject-movement limitations. It
was found that subjects wearing the pro
-
gressive addition lens with the narrower
intermediate zone (PAL2) exhibited
slightly smaller eye movements than with
the lens having a wider intermediate zone
(PAL1). On the other hand, in apparent
compensation for the restricted clear
field-of-view, subjects wearing PAL2 ex
-
hibited greater head movements than
PAL1. These findings have important
ramifications in the design of PAL lenses
for sports and in the workplace.
Dr. Hung has financial interest in the
wireless sensor system used in this study.
ACKNOWLEGMENT
We thank Abhijit Tamba and Wayne
Spencer for assistance with the experi-
ments.
Sources
a. http://www.codeproject.com/
b. The MathWorks
Natick, MA
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Corresponding author:
George K. Hung, Ph.D.
Dept. of Biomedical Engineering
Rutgers University
617 Bowser Road
Piscataway, NJ 08854
shoane@rci.rutgers.edu
Date accepted for publication:
August 9, 2006
Journal of Behavioral Optometry Volume 17/2006/Number 5/Page 119
EDITORIAL CONTINUED
almost 4%. This can be interpreted as
evidence that binocular difficulties
are given somewhat more attention
in the practice of primary care op
-
tometry than some have alleged.
The study lists the top 40 most
frequent diagnoses that were re
-
ported. Not surprisingly, the basic re
-
fractive conditions and presbyopia
accounted for almost 51% of the di
-
agnoses. However, taken together,
Accommodative Dysfunction, Re
-
fractive Amblyopia, Esotropia and
Convergence Insufficiency accounted
for 2.04% of the diagnoses. This is
close to the 2.45% for the combina
-
tion of Glaucoma Suspect and Open
Angle Glaucoma.
It must be pointed out that the
place of binocular vision disorders in
the entire profession is not repre
-
sented by the study; those in “special
-
ized practice” did not meet the
criteria for primary care optometric
practitioners. Nevertheless, I interpret
the report as indicating that, at least
in terms of diagnostics, binocular vi-
sion disorders remain an integral part
of primary care optometry. It is cer-
tainly not dead; rather, it is alive, but
not kicking. The study should pro-
vide valuable information for the
strategic planning of all organizations
involved with the education of op
-
tometrists, and particularly for the
Optometric Extension Program and
the College of Optometrists in Vision
Development.
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... These measures provide insight into the golfer's physiological and mental state. [5][6][7][8] These golf studies are the latest in a growing literature that attempts to unlock some of the mysteries surrounding this apparently simple act of putting. [9][10][11][12][13] The importance of putting is evident, as it comprises approximately 40% of one's total golf strokes during a typical round of golf. ...
... 14 Books, drills, and professional advice constantly describe the importance of minimizing EM and HM during the putting stroke. 7,9,10 One drill suggested that improved putting involves keeping one eye closed during the putting stroke. This drill is meant to improve stillness of both the head and the body during the putting stroke by concentrating on the ball. ...
... A compact disc (12 cm, or 4.7 inches in diameter) was used to represent the golf cup, and a stretch of green artificial turf was used as the putting surface. 7,8 A putt was considered successful if more than half the ball was inside the disc, and furthermore the ball speed was moderate enough so it would have dropped into an actual cup. Each putt was then scored on a simple "made versus missed" basis, and the putting results were recorded accordingly. ...
Article
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This study investigated the effect of psychological pressure on physiological responses during the golf putting stroke. Six young adults (four males and two females) participated in the study. The experiment was comprised of a contest that consisted of four sessions, with a dinner prize awarded to the winner. In each session , the subject was instructed to attempt 20, 9-foot putts. Eye, head, and putter motions, as well as heart rate and breathing rate, were objectively recorded during each trial. For all sessions, each successful putt was awarded a score of +2 points. However, as the four sessions progressed, any missed putt was given progressively greater negative scores:-2,-3,-4, and-5 points, respectively. At the end of the experiment , the subject rated the perceived pressure during each session on a scale of 1 to 5, with 1 corresponding to no pressure and 5 corresponding to extreme pressure. Overall, the results demonstrated that the apparently simple act of putting involves a complex interplay among various physiological and neurological control parameters , hence reflecting a myriad of emo-Borkowski R, Bernardo JC, Hung GK, Ciuffreda KJ, Effect of psychological pressure on eye, head, heart and breathing responses during the golf putting stroke. J Behav Optom 2009;20:35-41. tions that are magnified under increased psychological pressure.
... For example, Hung (2003) showed greater variability in eye and head movements for conventional golf putter grips than for either crossedhand or one-handed grips, while putt duration and accuracy were found to be greater than the conventional grip for one-handed and cross-handed grips, respectively. More recently, Hung et al. (2006) found significantly increased head movement and some increase in eye movements when wearing narrow-corridor vs wide-corridor PALs in presbyopic individuals. While these studies have begun to establish the impact of various factors on eye, head and putter movements related to the golf putt, there has been no formal study of the effect of retinal defocus on golf putting performance. ...
... A custom-designed, computer-based, head-mounted eye and head movement sensor system (patent pending) (Figures 1 and 2a), along with a putter-mounted position sensor (Figure 2b), were used to quantify the head, eye and putter movements, respectively, associated with the standard golf putt (Hung, 2003(Hung, , 2004Hung et al., 2006). The eye movement sensor was positioned in front of the subjectÕs left eye, which assessed horizontal eye position; the right eye was not monitored. ...
... Putter amplitude and putter duration were not affected, even at the maximum level of blur. These findings are in agreement with that of Hung et al. (2006), who found that different PALs had no effect on either putter amplitude or duration, despite their optical restrictions and modest peripheral blur present. This is consistent with the notion of it being based on motor learning, with relatively little sensory-based information necessary under their fixed distance condition. ...
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The purpose of this experiment was to determine the effect of type and magnitude of retinal defocus on golf putting accuracy, and on the related eye, head, and putter movements. Eye, head, and putter movements were assessed objectively along with putting accuracy in 16 young adult, visually normal inexperienced golfers during a fixed 9-foot golf putt. Convex spherical (+0.50 D, +1.00 D, +1.50 D, +2.00 D, +10.00 D) and cylindrical (+1.00 D x 90, +2.00 D x 90) lenses were added binocularly to create various types and magnitudes of retinal defocus. Putting accuracy was significantly reduced only under the highest spherical blur lens condition (+10.00 D). No significant differences were found between any other lens conditions for eye, head or putter movements. Small amounts of spherical and astigmatic retinal defocus had a minimal impact on overall golf putting performance, except for putting accuracy under the highest blur condition. This is consistent with the findings of related studies. For a fixed putting distance, factors other than quality of the retinal image, such as blur adaptation and motor learning, appeared to be sufficient to maintain a high level of motor performance.
... Previous studies have demonstrated that retinal defocus from either presbyopia or inappropriate refractive correction can lead to poorer putting results. 27,28 Maximizing the best visual acuity with corrective lenses or contacts is important for aiming, reading the speed of the greens, and determining the slope. Many golfers remove sunglasses when putting, especially polarized sunglasses which limit glare and thus hinder the detection of subtle undulations or break of the green. ...
... For the putting experiments, a wireless device for measuring head, eye, and putter motions was used (Hung and Ciuffreda, 2006). It consisted of a circuit board containing an accelerometer which was mounted atop a visor worn by the subject. ...
Conference Paper
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PURPOSE: To expand on our previous smaller study (ARVO 2007, #903) on the effect of oculomotor auditory feedback training on putting performance and eye and head stability during the golf putting stroke, by including more subjects and with the hole at a greater putting distance. METHOD: Twelve novice golfers participated in the study, with three of them serving as controls. Pre-Training Test: The subject attempted, without prior instructions, 40 putts to a standard size golf-hole 9 ft away. For each attempted putt, eye, head, and putter movements were recorded objectively over a 3-sec period using a wireless sensor system. Auditory Feedback Simulator Training (excluding the controls): At the end of the first day, as well as at the beginning of the subsequent day, the subject was trained using an oculomotor auditory feedback regimen for 15 minutes. Training consisted of attempting to maintain fixation within a criterion range of +/-10 cm (~ +/-4 deg) horizontally about a fixation target on a computer screen. Within this criterion range, the tone was extinguished, whereas outside this range, the tone was present. The subject was instructed to attempt to maintain fixation within the tone-free zone while making simulated putting strokes using the mouse. Post-Training Test: The procedure used in Pre-Training was repeated. For both the Pre-and Post-Training responses, eye movements were recorded using the infrared limbus reflection technique, and head and putter movements were recorded using onboard accelerometers. The eye and head signals were sent wirelessly to a PC via a circuit board mounted on the subject's visor, while the putter signal was sent via a circuit board mounted on the putter shaft. The data were analyzed over the interval from the beginning of the putt to the moment of ball impact. The root mean square (RMS) values of the eye and head signals within this time interval were calculated for each record, and the average value for the records in a session for each subject was obtained. All values were converted to equivalent cm of displacement on the putting surface. RESULTS: There was a trend showing better putting performance (37.9% vs. 32.4%, p < 0.1), and reduced mean RMS values of the eye movements (3.20 cm vs. 3.63cm, p < 0.1) and head movements (3.85 cm vs. 4.44 cm, p > 0.1), with oculomotor auditory feedback training. The control subjects exhibited response changes from Tasks 1 to 2 (i.e., without auditory feedback training) that were in the opposite direction as those found for the training protocol. CONCLUSIONS: Training using a simulator with oculomotor auditory feedback improved eye and head stability during the golf putting stroke, as well as putting accuracy. This result suggests that multi-sensory eye position error-based information can be combined at higher neural centers to enhance fixational oculomotor control.
... It has been described in detail elsewhere. 21 Briefly, it consisted of a circuit board containing an accelerometer that was mounted atop a visor worn by the subject. An infrared-reflection eye sensor, which was secured via a flexible cable to the side of the visor, was positioned in front the subject's left eye (Figures 1 and 2). ...
Article
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This study investigated the effect of ocu-lomotor-auditory feedback training on the stability of eye and head movements during the golf putting stroke and on putting performance. Twelve novice golfers participated in the study. Nine undertook training while three served as non-training controls. Initially, all subjects attempted 40 putts to a standard size golf-hole 9 feet away. Eye, head, and putter movements were recorded objectively using a wireless sensor system. The experimental subjects then used an oculomotor-auditory feedback regimen twice for 15 minutes each and attempted about 300 computer simulated trials. The 40 putts were then repeated for both groups. The data were analyzed for eye and head signals within the putting stroke time interval. The results showed a trend of better putting performance and reduced eye movements and head movements for the experimental subjects. The control subjects did not show these changes. This indicates that training using a simulator with ocu-lomotor-auditory feedback improved eye and head stability during the golf putting stroke and enhanced putting accuracy. This also suggests that multi-sensory eye position error-based information can be combined at higher neural centers to enhance fixational oculomotor control.
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Sports medicine is becoming a very popular means of addressing specific questions posed by athletes concerning the body’s forces and actions during athletic motions. It has, for example, provided valuable information about the golf swing and physical forces impacting on the golf ball (Hay, 1978; Nicklaus and Bowden, 2002). Much of this information has been obtained using high-speed photography (Barnes, 1919; Bobby Jones’ swing photograph, 1939; http://golfswingphotos.com). Indeed, the components of the golf swing have been studied in great detail over past 50 years. However, there is a surprising lack of objective simultaneous measurements of eye and head motion during the golf swing, especially in putting.
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To assess dynamic interactions of eye and head movements during return-sweep saccades (RSS) when reading with single-vision (SVL) versus progressive-addition (PAL) lenses in a simulated computer-based business environment. Horizontal eye and head movements were recorded objectively and simultaneously at a rate of 60 Hz during reading of single-page (SP; 14 degrees horizontal [H]) and double-page (DP; 37 degrees H) formats at 60 cm with binocular viewing. Subjects included 11 individuals with normal presbyopic vision aged 45 to 71 years selected by convenience sampling from a clinic population. Reading was performed with three types of spectacle lenses with a different clear near field of view (FOV): a SVL (60 degrees H clear FOV), a PAL-I with a relatively wide intermediate zone (7.85 mm; 18 degrees H clear FOV), and a PAL-II with a relatively narrow intermediate zone (5.60 mm; 13 degrees H clear FOV). Eye movements were initiated before head movements in the SP condition, and the reverse was found in the DP condition, with all three lens types. Duration of eye movements increased as the zone of clear vision decreased in the SP condition, and they were longer with the PALs than with the SVL in the DP condition. Gaze stabilization occurred later with the PALs than with the SVL in both the SP and DP conditions. The duration of head movements was longer with the PAL-II than with the SVL in both the SP and DP conditions. Eye movement peak velocity was greater with the SVL than the PALs in the DP condition. Eye movement and head movement strategies and timing were contingent on viewing conditions. The longer eye movement duration and gaze-stabilization times suggested that additional eye movements were needed to locate the clear-vision zone and commence reading after the RSS. Head movements with PALs for the SP condition were similarly optically induced. These eye movement and head movement results may contribute to the reduced reading rate and related symptoms reported by some PAL wearers. The dynamic interactions of eye movements and head movements during reading with the PALs appear to be a sensitive indicator of the effect of lens optical design parameters on overall reading performance, because the movements can discriminate between SVL and PAL designs and at times even between PALs.
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The objective of this article is to determine the effect of three different putting grips (conventional, cross-hand, and one-handed) on variations in eye and head movements during the putting stroke. Seven volunteer novice players, ranging in age from 21 to 22 years, participated in the study. During each experimental session, the subject stood on a specially designed platform covered with artificial turf and putted golf balls towards a standard golf hole. The three different types of grips were tested at two distances: 3 and 9 ft. For each condition, 20 putts were attempted. For each putt, data were recorded over a 3-s interval at a sampling rate of 100 Hz. Eye movements were recorded using a helmet-mounted eye movement monitor. Head rotation about an imaginary axis through the top of the head and its center-of-rotation was measured by means of a potentiometer mounted on a fixed frame and coupled to the helmet. Putter-head motion was measured using a linear array of infrared phototransistors embedded in the platform. The standard deviation (STD, relative to the initial level) was calculated for eye and head movements over the duration of the putt (i.e., from the beginning of the backstroke, through the forward stroke, to impact). The averaged STD for the attempted putts was calculated for each subject. Then, the averaged STDs and other data for the seven subjects were statistically compared across the three grip conditions. The STD of eye movements were greater (p < 0.1) for conventional than cross-hand (9 ft) and one-handed (3 and 9 ft) grips. Also, the STD of head movements were greater (p < 0.1; 3 ft) for conventional than cross-hand and one-handed grips. Vestibulo-ocular responses associated with head rotations could be observed in many 9 ft and some 3 ft putts. The duration of the putt was significantly longer (p < 0.05; 3 and 9 ft) for the one-handed than conventional and cross-hand grips. Finally, performance, or percentage putts made, was significantly better (p < 0.05; 9 ft) for cross-hand than conventional grip. The smaller variations, both in eye movements during longer putts and head movements during shorter putts, using cross-hand and one-handed grips may explain why some golfers, based on their playing experience, prefer these over the conventional grip. Also, the longer duration for the one-handed grip, which improves tempo, may explain why some senior players prefer the long-shaft (effectively one-handed grip) putter.
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purpose. Reading with two different intermediate progressive lens designs was investigated regarding eye and head movement patterns and compared with movement patterns with a conventional single vision lens in a computer-based work environment. methods. Two-dimensional eye (horizontal, vertical) and three-dimensional head (horizontal, vertical, and torsional) movements were recorded objectively and simultaneously at a rate of 60 Hz during reading of moderate contrast (40%) single- and double-page text formats at 60 cm with binocular viewing. In addition, global reading ability was rated subjectively for each lens. Subjects were 11 visually normal, presbyopic individuals aged 45 to 71 years selected by convenience sampling from a clinic population. Reading was performed with three types of spectacle lenses: a single-vision lens (SVL; 60° horizontal [H] clear field-of-view [FOV]); a progressive addition lens (PAL) with a relatively wide intermediate zone (PAL-I; 7.85 mm, 18°H clear FOV); and a PAL with a relatively narrow intermediate zone (PAL-II; 5.60 mm, 13°H clear FOV). results. Many reading-related parameters, as well as eye- and head-movement parameters, were adversely affected by the PALs compared with the SVL. One reading-related parameter (i.e., number of regressions) differentiated between PALs. Subjective rating of global reading ability was highest with the SVL and lowest with the PAL-II. conclusions. The optical design of a spectacle lens had significant impact on reading performance and on the combined eye-head movements initiated during reading. Both horizontal eye and head movements discriminated well between PALs and the SVL, but not between PALs, despite subjective preferences. This suggests that nonoculomotor factors contribute to patients’ nonacceptance of PALs. Vertical eye and head movements and torsional head movements were not as discriminatory as were their horizontal counterparts.
Conference Paper
Purpose: To determine the effect of three different putting grips: conventional, cross-hand, and one-handed, on variations in eye and head movements during the putting stroke. Methods: Seven volunteer novice players, ranging in age from 21 to 22 years, participated in the study. During each experimental session, the subject stood on a specially-designed platform covered with artificial turf and putted golf balls towards a standard golf hole. The three different types of grips were tested at two distances: 3 ft and 9 ft. For each condition, 20 putts were attempted. For each putt, data were recorded over a 3 sec interval at a sampling rate of 100 Hz. Eye movements were recorded using a helmet-mounted eye movement monitor. Head rotation about the spine axis was measured by means of a potentiometer mounted on a fixed frame and coupled to the helmet. Putter-head motion was measured using a linear array of infrared phototransistors embedded in the platform. The standard deviation (std, relative to the initial level) was calculated for eye and head movements over the duration of the putt (i.e., from the beginning of the backstroke, through the forward stroke, to impact). The averaged std for the attempted putts was calculated for each subject. Then, the averaged stds and other data for the seven subjects were statistically compared across the three grip conditions. Results: The std of eye movements were significantly greater (p < 0.1) for conventional than cross-hand (9 ft) and one-handed (3 and 9 ft) grips. Also, the std of head movements was significantly greater (p < 0.1; 3 ft) for conventional than cross-hand and one-handed grips. Vestibulo-ocular responses associated with head rotations could be observed in many 9 ft and some 3 ft putts. The duration of the putt was significantly longer (p < 0.05; 3 and 9 ft) for the one-handed than conventional and cross-hand grips. Finally, performance, or percentage putts made, was significantly better (p < 0.05; 9 ft) for cross-hand than conventional grip. Conclusion: The smaller variations, both in eye movements during longer putts and head movements during shorter putts, using cross-hand and one-handed grips may explain why some golfers, based on their playing experience, prefer these over the conventional grip. Also, the longer duration for the one-handed grip, which improves tempo, may explain why some senior players prefer the long-shaft (effectively one-handed grip) putter.
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1. A simple but accurate method of measuring the depth of field of the eye is described. 2. At a fixed pupil size the hyperfocal distance was found to increase directly with the log of the background luminance. 3. If the retinal illumination is held constant and the pupil size is altered, the depth of field varies approximately inversely with the pupil diameter. With pupil diameters greater than 2.5 mm the observed deviation from theoretical expectation can be accounted for by the operation of the retinal direction effect of Stiles and Crawford. 4. Further evidence that the retinal direction effect modifies depth of field has been obtained by measurement with fields of different colour but similar luminance. 5. The correction of chromatic aberration in the eye by means of an achromatizing lens decreases depth of field. 6. The minimum estimate for depth of field obtained under optimum conditions was ± 0.3 D at a pupil diameter of 3 mm.
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The purpose of this paper was to study the prevalence of nonstrabismic accommodative and binocular dysfunctions in a clinical population. We examined 265 symptomatic patients who were chosen from an optometric clinic. We performed several tests to diagnose any form of refractive, accommodative or binocular dysfunction. Of the 265 subjects examined, 59 patients (22.3%) had some form of accommodative or binocular dysfunction and required not just the correction of the refractive error but a specific treatment for each of the problems diagnosed. The remaining subjects were classed as having refractive anomalies. The frequency of binocular dysfunctions was 12.9%, and 9.4% for accommodative anomalies. Convergence excess (4.5%) was more prevalent than convergence insufficiency (0.8%) and accommodative excess (6.4%) more prevalent than accommodative insufficiency (3%).
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The prevalence of general binocular dysfunction with asthenopia was determined for non-presbyopes at an urban optometry clinic serving municipal workers and their dependents. Of the sample of 119 patients, 42.9% had jobs with heavy desk work demands (primarily secretarial and clerical) and 39.5% were students. The prevalence of symptomatic general binocular dysfunction was 21.0%. Accommodative dysfunctions were the most commonly encountered condition at 16.8%. Symptomatic near esophoria was found in 5.9% of patients and convergence insufficiency in 4.2%. Both vergence dysfunctions overlapped with accommodative dysfunctions.
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As a result of lens design limitations, progressive addition lenses (PAL's) present a limited field of view for tasks at intermediate distances, such as with computers. To assess whether this limitation results in diminished visual performance, PAL's were compared with single-vision lenses in four different types of reading tasks in a computer workplace environment. Adult subjects performed four computer-based reading tasks using both single-vision lenses and PAL's at an intermediate distance of 64 cm. Single-vision lenses performed significantly better than PAL's in one task, with a trend for better performance in another task. There was no difference in performance for the remaining two tasks. Visual performance tests that involved stimuli subtending the widest visual angles and demanded more fixational shifts were more sensitive in discerning performance differences between the lens designs. In general, PAL's showed marginally diminished performance compared with single-vision lenses, presumably due to their restricted intermediate channel.