ArticlePDF Available

Effect of variable tinted spectacle lenses on visual performance in control subjects

Authors:
Jason E Lee
Jason E Lee
Jason E Lee
  • This person is not on ResearchGate, or hasn't claimed this research yet.
Jonathan J Stein
Jonathan J Stein
Jonathan J Stein
  • This person is not on ResearchGate, or hasn't claimed this research yet.
Meredith B Prevor
Meredith B Prevor
Meredith B Prevor
  • This person is not on ResearchGate, or hasn't claimed this research yet.
William Seiple at New York University
William Seiple
Show all 7 authorsHide
Download full-text PDF
Read full-text
Download citation

Abstract and Figures

To evaluate quantitatively the effects of tinted spectacle lenses on visual performance in individuals without visual pathology. Twenty-five subjects were assessed by measuring contrast sensitivity with and without glare. Gray, brown, yellow, green, purple, and blue lens tints were evaluated. Measurements were repeated with each lens tint and with a clear lens, and the order was counterbalanced within and between subjects. Glare was induced with a modified brightness acuity tester. All subjects demonstrated an increase in contrast thresholds under glare conditions for all lens tints. However, purple and blue lens tints resulted in the least amount of contrast threshold increase; the yellow lens tint resulted in the largest contrast threshold increase. Purple and blue lens tints may improve contrast sensitivity in control subjects under glare conditions.
Figures - uploaded by William Seiple
Author content
All figure content in this area was uploaded by William Seiple
Content may be subject to copyright.
Content uploaded by William Seiple
Author content
All content in this area was uploaded by William Seiple on Oct 29, 2019
Content may be subject to copyright.
Effect of Variable Tinted Spectacle Lenses on
Visual Performance in Control Subjects
Jason E. Lee, Jonathan J. Stein, M.D., Meredith B. Prevor,
William H. Seiple, Ph.D., Karen Holopigian, Ph.D.,
Vivienne C. Greenstein, Ph.D., Susan M. Stenson, M.D.
Purpose. To evaluate quantitatively the effects of tinted spectacle
lenses on visual performance in individuals without visual pathol-
ogy. Methods. Twenty-five subjects were assessed by measuring
contrast sensitivity with and without glare. Gray, brown, yellow,
green, purple, and blue lens tints were evaluated. Measurements
were repeated with each lens tint and with a clear lens, and the
order was counterbalanced within and between subjects. Glare was
induced with a modified brightness acuity tester. Results. All
subjects demonstrated an increase in contrast thresholds under
glare conditions for all lens tints. However, purple and blue lens
tints resulted in the least amount of contrast threshold increase; the
yellow lens tint resulted in the largest contrast threshold increase.
Conclusions. Purple and blue lens tints may improve contrast
sensitivity in control subjects under glare conditions.
Key Words: Contrast sensitivity—Contrast threshold—Tinted
lenses—Colored lenses—Variable tint lenses—Glare testing—
Disability glare.
Vision researchers have long tried to elucidate whether colored
lenses have an effect on visual performance. In a review of nearly
100 published reports, Clark
1
noted a variety of anecdotal benefits
from filters of various types and colors, although little objective
data was available. More recently, there have been some data
suggesting improved clarity of vision and reduced glare using
yellow-tinted lenses.
2
Yellow filters may also improve the contrast
sensitivity function of normal observers,
2
although this has been
disputed.
3
The use of yellow-tinted lenses improves reaction time
of normal subjects in response to grating stimuli, particularly
low-contrast targets of intermediate spatial frequencies.
4
In addi-
tion, yellow-tinted lenses may increase the apparent brightness of
large targets under daylight conditions.
5
Although recent studies
have examined the effects of yellow lenses, which have been
preferred by aviation pilots, marksmen, skiers, and people with
low vision, objective data for a variety of different colored lenses
are not readily available.
Contrast sensitivity is a measure of the amount of contrast
required to detect or recognize a target, and it describes one’s
ability to recognize large, low-contrast patterns. This test has been
promoted for use in clinical vision testing, and it differs from
standard visual acuity testing, which measures the ability to re-
solve fine detail at high contrast.
6
Following the work of early
pioneers,
7–9
most researchers have used patterns of alternating
light and dark bars called sine-wave gratings, which can vary in
spatial frequency (the number of light-dark cycles per degree). A
graphical representation of contrast sensitivity as a function of the
spatial frequency is called the contrast sensitivity function, which
may vary with age and ocular pathology.
10
The lowest degree of
contrast that an observer may consistently detect is called the
contrast threshold, and thus a lower threshold corresponds to better
visual performance.
Disability glare refers to the reduced visibility of a target caused
by the presence of a light source elsewhere in the visual field.
Opacities and inconsistencies in the ocular media cause intraocular
light scatter, which reduces the contrast of the image on the retina.
6
Disability glare testing measures the extent to which the glare
source impairs visibility of the target,
11
and it serves as a method
for isolating vision loss due to intraocular light scatter.
12
The goal of this study was to evaluate the effects of tinted
spectacle lenses of various colors on contrast sensitivity and
disability glare testing in subjects without ocular pathology.
METHODS
Twenty-five subjects (mean age 26.8 ⫾2.55 years; 17 men, 8
women) with no known visual pathology were enrolled in the
study. Best-corrected monocular letter acuity ranged from 20/15
to 20/25.
A clear lens and the following tinted lenses with 50% transmit-
tance were used in the study: gray, brown, yellow, green, purple,
and blue (equivalent to activated variable tint lenses, provided by
Transitions Optical, Inc., Pinellas Park, FL). Transmittance and
color values (Table 1) as well as absorption spectra for each lens
are provided (Fig. 1).
Best-corrected monocular contrast thresholds were measured
using computer software (Morphonome Image Psychophysics
Software, version 4.0, Smith-Kettlewell Eye Research Institute,
San Francisco, CA). Subjects were placed at a viewing distance of
1.44 m. The computer monitor was illuminated with two light
sources (Sylvania Par 38 floodlight, 150 W, 130 V; OSRAM
Accepted November 16, 2001.
From the Department of Ophthalmology, New York University Medical
Center, New York, New York.
Address reprint requests to William H. Seiple, Ph.D., 550 First Avenue,
NB 5N16, New York, NY 10016. Address correspondence to Susan
Stenson, M.D., 550 First Avenue, NB 5N18, New York, NY 10016.
E-mail: suestenson@aol.com.
The CLAO Journal 28(2): 80–82, 2002 © 2002 Lippincott Williams & Wilkins, Inc.
80
Sylvania, Westfield, IN) placed at a distance of 3 m from the
monitor and1mtoeach side of the subject. The stimulus was a
series of achromatic sine wave gratings of 0.4, 1.0, and 4.0 cycles
per degree (cpd). Contrast threshold measurements were repeated
using each of the six tints and a clear lens, and the order of the
lenses was counterbalanced within and between subjects.
The effects of the tinted lenses on contrast thresholds were
quantified with and without glare. Glare was induced with a
modified brightness acuity tester, utilizing a circular light source
(Marvel circular fluorescent, 10 cm diameter, 22 W, 5000 K, 1050
lumens; Marvel Lighting Corp., Peabody, MA) placed 15 cm in
front of the eye such that the line of sight passed through the center
of the light source.
RESULTS
Contrast thresholds varied significantly with spatial frequency,
F
2,48
⫽7.52, P⬍.001, and the lowest threshold was found in the
4.0 cpd condition (Fig. 2). Data were further analyzed for the 4.0
TABLE 1. Lens Characteristics
Lens color Ya*b*
Gray 49.3 0.81 ⫺2.06
Brown 50.3 6.9 14.7
Yellow 49.6 6.1 97.6
Green 50.5 ⫺18.9 21.2
Purple 50.8 16.3 ⫺20.8
Blue 50.2 ⫺15.0 ⫺30.1
Y, transmittance (%); a
*, red/green color coordinate; b
*, yellow/blue color coordinate.
FIG. 1. Absorbance as a function of the wavelength of light passing through each lens. Absorption
is expressed as a logarithmic function of transmittance (absorbance of 1 ⫽10% transmission,
absorbance of 2 ⫽1% transmission).
FIG. 2. A comparison of contrast threshold as a function of spatial
frequency under conditions with and without glare.
81EFFECT OF VARIABLE TINTED SPECTACLE LENSES
The CLAO Journal, Vol. 28, No. 2, 2002
cpd condition, using a 2 (glare: glare vs. no glare) ⫻7 (lens color:
clear vs. green vs. gray vs. brown vs. purple vs. yellow vs. blue)
repeated measures analysis of variance. Glare and lens color were
within subject factors. For the 4.0 cpd condition, there was a
significant main effect of glare, F
1,24
⫽7.62, P⬍.011 (M no
glare ⫽1.58, standard deviation [SD] ⫽1.19; M glare ⫽2.20,
SD ⫽2.23). This indicates that control subjects demonstrated a
significant increase in contrast thresholds under glare conditions
for all lens tints. The effect was least for the purple and blue lens
tints, and greatest for the yellow lens tint (Fig. 3). There was not
a significant main effect of lens color, F
6,24
⫽1.44, P⫽.20. There
was also no significant interaction between lens and glare, F
6,144
⫽
0.50, P⫽.80.
DISCUSSION
Contrast thresholds were lowest at a frequency of 4.0 cpd, a
result that is consistent with the contrast sensitivity function for
this age group.
10
The glare source was effective in producing a
measurable contrast threshold increase for each of the lenses.
Trends indicate that purple and blue tints may provide some
benefit under conditions of glare. Further studies may be helpful in
examining the possible effects of these colors on visual perfor-
mance.
Although previous reports have described potential benefits of
yellow lenses,
1–5
this study did not find a measurable improvement
in contrast sensitivity for an achromatic stimulus viewed through a
yellow lens. A recent study offers an explanation for the preference
of yellow lenses by outdoor enthusiasts, such as aviation pilots,
marksmen, and skiers. Yellow lenses improved contrast sensitivity
for a white stimulus upon a blue background, which suggests that
the benefit occurs only in the setting of a predominantly blue
background, such as the sky.
13
Further studies may find measur-
able improvements in contrast sensitivity using a variety of lens
tints to view targets and backgrounds of selected colors.
CONCLUSIONS
Although previous reports have described subjective prefer-
ences for a variety of lens tints, quantifying improvements in
visual performance by objective methods remains a valuable goal.
Purple and blue lenses may improve contrast sensitivity in normal
subjects under conditions of disability glare, and further investi-
gation may be warranted. Future studies may reveal an enhance-
ment in contrast sensitivity using various lens tints to view targets
and backgrounds of selected colors.
REFERENCES
1. Clark BA. Color in sunglass lenses. Am J Optom Arch Am Acad Optom
1969;46:825–840
2. Yap M. The effect of a yellow filter on contrast sensitivity. Ophthalmic
Physiol Opt 1984;4:227–232
3. Kelly SA, Goldberg SE, Bunton TA. Effect of yellow-tinted lenses on
contrast sensitivity. Am J Optom Physiol Opt 1984;61:657–662
4. Kinney J, Schlichting C, Neri D, et al. Reaction time to spatial
frequencies using yellow and luminance-matched neural goggles. Am J
Optom Physiol Opt 1983;60:132–138
5. Kelly SA. Effect of yellow-tinted lenses on brightness. J Opt Soc Am
A 1990;A7:1905–1911
6. American Academy of Ophthalmology. Contrast sensitivity and glare
testing in the evaluation of anterior segment disease. Ophthalmology
1990;97:1233–1237
7. Schade OH. Optical and photoelectric analog of the eye. J Opt Soc Am
A1956;46:721–739
8. Campbell FW, Robson JG. Application of Fourier analysis to the
visibility of gratings. J Physiol 1968;197:551–566
9. Campbell FW, Green DG. Optical and retinal factors affecting visual
resolution. J Physiol 1965;181:576–593
10. Arundale K. An investigation into the variation of human contrast
sensitivity with age and ocular pathology. Br J Ophthalmol 1978;62:
213–215
11. Bailey IL, Bullimore MA. A new test for the evaluation of disability
glare. Optom Vis Sci 1991;68:911–917
12. Van der Berg TJTP. Importance of pathological intraocular light
scatter for visual disability. Doc Ophthalmol 1986;61:327–333
13. Wolffsohn JS, Cochrane AL, Khoo H, et al. Contrast is enhanced by
yellow lenses because of selective reduction of short-wavelength light.
Optom Vis Sci 2000;77:73–81
FIG. 3. A comparison of the increase in contrast threshold expe-
rienced with each lens under conditions with glare, relative to
conditions without glare, at a spatial frequency of 4.0 cpd.
82 LEE ET AL.
The CLAO Journal, Vol. 28, No. 2, 2002
... Tinted lenses reduce high brightness, improve our ability to see reflective and relatively less detailed content. 66,67 Comparable improvements were not revealed for chromatic tasks that contained colour visual stimuli. Shaik et al. 67 found the greatest performance reductions were caused by blue tinted spectacles, with grey lenses showing some improvements over the former and brown. ...
... 80 Blue and purple tinted lenses proved to be effective in reducing large contrast differences produced by glare, leading to notable improvements in both contrast sensitivity and clarity. 66 Similar findings also advocated the use of blue or clear lenses in situations necessitating increased contrast sensitivity at high spatial frequencies. 67 This study revealed that the most prominent improvements were in relation to low spatial frequency content, while were subdued for high spatial frequencies. ...
The design of window shades and fenestration for view clarity
Article
Full-text available
  • Aug 2024
The ability to discern the content of the view through a window is referred to as view clarity. It is often overlooked in the design process, and the methods of shading daylight can affect window views. We conducted a narrative review of building standards and the scientific literature to better understand how shades can be designed so as to retain the window view. View clarity was characterised by three main dimensions: (1) the shading solution, (2) the view content and (3) the observer. Each dimension and the interactions between them influence view clarity. These interactions make it difficult to predict view clarity for all the situations that can occur in buildings. Nonetheless, we highlighted the effects of different shades on the view clarity. Our insights can help designers consider these impacts within the context of overall window design.
View
... Among the multifaceted dimensions of visual performance, contrast sensitivity (CS), color vision (CV), and visual reaction time (VRT) emerge as pivotal factors [1,2]. CS, the ability to discern minute and substantial pattern contrasts, profoundly influences visual recognition [3]. Notably, an individual with good visual acuity may still exhibit impaired CS, underscoring the significance of this facet. ...
Impact of Tinted Lenses on Contrast Sensitivity, Color Vision, and Visual Reaction Time in Young Adults
Article
Full-text available
  • Nov 2023
Background Visual performance relies on essential functions such as contrast sensitivity, color vision, and visual reaction time. While studies have suggested that tinted lenses can enhance these visual functions, their effects on specific aspects remain insufficiently explored. Understanding the potential benefits and implications of tinted lenses is crucial for prescription considerations. This study aims to address this gap by evaluating the influence of tinted lenses on visual functions in young emmetropic adults. Methodology This prospective, cross-sectional study, approved by the institutional research and ethics committee, encompassed three key assessments, namely, contrast sensitivity using the Pelli-Robson chart, color vision with the D-15 test, and visual reaction time utilizing the Hit-the-dots method. The study involved 100 participants aged 18-30 years with normal vision, while individuals with color vision deficiencies, refractive errors, amblyopia, and strabismus were excluded. Assessments were conducted both with and without blue, yellow, brown, and gray-tinted lenses. Contrast sensitivity was quantified in logMAR units, color vision was evaluated using a color disc arrangement, and visual reaction time was measured with a 30-second reaction test employing an Asus Vivo Book. Data were analyzed using Friedman’s two-way analysis of variance by ranks, and specific differences were identified through the Dunn-Bonferroni method. Results The average age of the participants was 22.8 (2.8) years, with all participants exhibiting distance visual acuity of 6/6 and near visual acuity of N6. Contrast sensitivity values were consistent at 2.00 logMAR, indicating good contrast sensitivity, irrespective of the presence of tinted lenses. Notably, among the participants, yellow tint 50 (50%) emerged as the preferred choice for visualizing low-contrast optotypes. Friedman’s test revealed significant differences in color vision and visual reaction time between normal and tinted lenses (p < 0.001). The Dunn-Bonferroni test further indicated significant differences, particularly with yellow tint (p < 0.05) compared to other tints. In visual reaction time, significance (p < 0.05) was observed for all comparisons except between blue and gray, with the yellow tint demonstrating the best reaction time (median = 23) compared to other tints. Conclusions This research provides valuable insights into the impact of tinted lenses on contrast sensitivity, color vision, and visual reaction time in individuals with normal vision. Importantly, the use of yellow tint appears to enhance rapid reactions and contrast perception. Nevertheless, the selection of tint types should be thoughtfully tailored to individual occupational needs and personal preferences, taking into account their potential effects on color perception.
View
... Through more complete visual examination, decreased contrast sensitivity in TBI patients can be detected and managed (Barnett and Singman, 2015). In treating contrast sensitivity deficits, some have advocated utilizing tinted lenses to increase contrast sensitivity, specifically under glare conditions (Lee et al., 2002;Lacherez et al., 2013). ...
Traumatic brain injury: Mechanisms, manifestations, and visual sequelae
Article
Full-text available
  • Feb 2023
Traumatic brain injury (TBI) results when external physical forces impact the head with sufficient intensity to cause damage to the brain. TBI can be mild, moderate, or severe and may have long-term consequences including visual difficulties, cognitive deficits, headache, pain, sleep disturbances, and post-traumatic epilepsy. Disruption of the normal functioning of the brain leads to a cascade of effects with molecular and anatomical changes, persistent neuronal hyperexcitation, neuroinflammation, and neuronal loss. Destructive processes that occur at the cellular and molecular level lead to inflammation, oxidative stress, calcium dysregulation, and apoptosis. Vascular damage, ischemia and loss of blood brain barrier integrity contribute to destruction of brain tissue. This review focuses on the cellular damage incited during TBI and the frequently life-altering lasting effects of this destruction on vision, cognition, balance, and sleep. The wide range of visual complaints associated with TBI are addressed and repair processes where there is potential for intervention and neuronal preservation are highlighted.
View
... It seems fairly obvious that colored �lters will enhance contrast whenever the wavelength difference between an object and its surround/background is enhanced by selective absorption by the �lter [104][105][106][107][108][109][110][111]. When the luminance ratio between the target and a background is close, this process will be enhanced due to the phenomenon of brightness induction. ...
The relationship between retinal carotenoids and cognitive function in healthy and cognitively impaired elders
Article
Full-text available
  • Apr 2012
Lutein (L) and zeaxanthin (Z) are incorporated into the neural retina as macular pigment (MP), which is a biomarker of L+Z distributed throughout the cortex. Cortical L+Z may have the ability to improve cognitive function. The purpose of this study was to determine whether or not MP relates to cognition in healthy elders and elders with mild cognitive impairment (MCI). 41 elders (M = 75.5 ± 6.3 years) participated. 15 of the 41 elders met criteria for MCI. MP density was measured psychophysically, and cognition was assessed via the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Visual processing speed was also measured. MP density was related to cognitive function in the visuospatial (r = 0.43, p < 0.05) and attentional (r = 0.47, p < 0.05) domains of the RBANS in elders with MCI, but not in unimpaired elders. Elders with MCI were also less sensitive to flicker. These results suggest that MP's relationship to cognition varies with cognitive impairment.
View
... 27 Yellow tints have been shown to improve depth perception, contour recognition, and reaction times. [28][29][30][31][32][33][34][35][36][37][38][39][40] Of note, many of these studies were conducted under artificial lighting conditions that are far below the intensity (in candelas per square meter) of natural sunlight, and this factor may obfuscate the enhancement effects. ...
Nutraceuticals for Visual Performane
Article
  • Dec 2019
Eye care professionals have several options to help athletes see their sport better. Recent placebo-controlled research has demonstrated that the carotenoids lutein (L) and zeaxanthin (Z) can improve visual performance factors in healthy eyes. The history, mechanisms of action, as well as their effects and potential benefits as shown in well-controlled trials are reviewed. A detailed description of how potential improvements in visual performance may apply to batting in baseball is provided. Recommendations for athletes with regard to modifications of diet to increase intake of carotenoids, or supplementation with purified forms of L and Z are discussed.
View
... These cells, though only making up <1% of retinal ganglion cells, are of great importance to non-visual functions, such as entrainment of circadian rhythms in physiology and behaviour to the environmental lightdark cycle, and the suppression of melatonin in response to light. 4 Previous investigations have examined the effects of filters manipulating short-wavelength light on visual performance, [5][6][7][8][9][10][11][12][13] colour vision, 11,[13][14][15] and steady-state and dynamic parameters of pupil size. 16,17 Furthermore, they have received attention in the domain of sleep medicine and chronobiology, where their effects on melatonin suppression, [18][19][20][21][22][23][24][25] circadian rhythms, [26][27][28][29][30] sleep, 6,17,21,25,[29][30][31][32][33] modulation of alertness by light, 34,35 and for use by shift or night workers 36,37 have been investigated. ...
Visual and non‐visual properties of filters manipulating short‐wavelength light
Article
Full-text available
  • Nov 2019
Purpose: Optical filters and tints manipulating short-wavelength light (sometimes called 'blue-blocking' or 'blue-attenuating' filters) are used in the management of a range of ocular, retinal, neurological and psychiatric disorders. In many cases, the only available quantification of the optical effects of a given optical filter is the spectral transmittance, which specifies the amount of light transmitted as a function of wavelength. Methods: We propose a novel physiologically relevant and retinally referenced framework for quantifying the visual and non-visual effects of these filters, incorporating the attenuation of luminance (luminous transmittance), the attenuation of melanopsin activation (melanopsin transmittance), the colour shift, and the reduction of the colour gamut (gamut reduction). Using these criteria, we examined a novel database of spectral transmittance functions of optical filters (n = 121) which were digitally extracted from a variety of sources. Results: We find a large diversity in the alteration of visual and non-visual properties. The spectral transmittance properties of the examined filters vary widely, in terms of shapes and cut-off wavelengths. All filters show relatively more melanopsin attenuation than luminance attenuation (lower melanopsin transmittance than luminous transmittance). Across the data set, we find that melanopsin transmittance and luminous transmittance are correlated. Conclusions: We suggest that future studies and examinations of the physiological effects of optical filters quantify the visual and non-visual effects of the filters beyond the spectral transmittance, which will eventually aid in developing a mechanistic understanding of how different filters affect physiology. We strongly discourage comparing the downstream effects of different filters on, e.g. sleep or circadian responses, without considering their effects on the retinal stimulus.
View
... These cells, though only making up <1% of retinal ganglion cells, are of great importance to non-visual functions, such as entrainment of circadian rhythms in physiology and behaviour to the environmental lightdark cycle, and the suppression of melatonin in response to light. 4 Previous investigations have examined the effects of filters manipulating short-wavelength light on visual performance, [5][6][7][8][9][10][11][12][13] colour vision, 11,[13][14][15] and steady-state and dynamic parameters of pupil size. 16,17 Furthermore, they have received attention in the domain of sleep medicine and chronobiology, where their effects on melatonin suppression, [18][19][20][21][22][23][24][25] circadian rhythms, [26][27][28][29][30] sleep, 6,17,21,25,[29][30][31][32][33] modulation of alertness by light, 34,35 and for use by shift or night workers 36,37 have been investigated. ...
Visual and non-visual properties of filters manipulating short-wavelength light
Preprint
Full-text available
  • Apr 2019
Optical filters and tints manipulating short-wavelength light (so-called "blue-blocking" or "blue-attenuating") are used as a remedy for a range of ocular, retinal, neurological and psychiatric disorders. In many cases, the only available quantification of the optical effects of a given optical filter is the spectral transmittance, which specifies the amount of light transmitted as a function of wavelength. Here, we propose a novel physiologically relevant and retinally referenced framework for quantifying the visual and non-visual effects of these filters, incorporating the attenuation of luminance (luminance factor), the attenuation of melanopsin activation (melanopsin factor), the shift in colour, and the reduction of the colour gamut (gamut factor). We examined a novel data base of optical transmittance filters (n=120) which were digitally extracted from a variety of sources and find a large diversity in the alteration of visual and non-visual properties. We suggest that future studies and examinations of the physiological effects of optical filters quantify the visual and non-visual effects of the filters beyond the spectral transmittance, which will eventually aid in developing a mechanistic understanding of how different filters affect physiology.
View
... 18 Blue colour causes the least amount of contrast threshold increase. 19 Sustained cells in the parvocellular pathway function to mediate the visual acuity, contrast sensitivity, colour vision and high spatial frequency. The ChromaGen blue filter lens restricts the incoming light by reducing the stimulation of the red and green cones relative to blue. ...
Does the chromagen blue filter lens affect the reading speed, accuracy and contrast sensitivity
Article
Full-text available
  • Mar 2019
  • Med J Malaysia
Purpose: To determine the effects of ChromaGen blue filter lens in reading speed, accuracy and contrast sensitivity. Methods: A cross-over, randomised study was carried out on 40 individuals (11 males and 29 females) aged 21 to 30 years. The rate of reading and reading accuracy was calculated with and without ChromaGen blue filter lens in all subjects. Wilkins Rate of Reading Test was used to measure the rate of reading and reading accuracy. Contrast sensitivity was also evaluated by using with and without the ChromaGen blue filter lens. Results: The mean rate of reading with and without ChromaGen blue filter lens was 160.58±16.03 words per minute and 150.52±15.66 words per minute respectively, with significant difference of p<0.001. The mean of reading accuracy (words correctly read per minute) in subjects, with ChromaGen blue filter was 149.30±0.79 words and without using filter lens was 148.53±1.11 words and found to be significant (p<0.001). There was no significant difference in the contrast sensitivity between subjects with and without the ChromaGen blue filter lens (p=0.083). No significant correlation was noted between the reading speed with age, spherical equivalent, contrast sensitivity, and reading accuracy. Conclusion: This study concludes that there was an increase of 6.68% in the rate of reading and improvement of 0.52% in accuracy among subjects with ChromaGen blue filter lens.
View
Assessing the impact of glazing and window shade systems on view clarity
Article
Full-text available
  • Aug 2024
Windows provide access to daylight and outdoor views, influencing building design. Various glazing and window shade materials are used to mitigate glare, overheating and privacy issues, and they affect view clarity. Among them, we evaluated the effect of window films, electrochromic (EC) glass, and fabric shades on view clarity. We conducted an experiment with 50 participants using visual tests adapted from clinical vision tests (visual acuity, contrast sensitivity, color sensitivity) and images displayed on a computer monitor in a controlled laboratory. Window films and EC glass tints outperformed fabric shades in visual acuity, contrast sensitivity and view satisfaction with the exception of the darkest EC tint state and dark grey VLT 3% shade for color sensitivity and view satisfaction. The EC tints pose internal reflection issues and fabric shades are preferred for visual privacy. Window films and EC glass hinder participants’ blue–green color discrimination while fabric shades also decrease red–yellow color discrimination. Visual acuity predicts view satisfaction and contrast sensitivity is the strongest predictor for visual privacy. Generally, higher visible light transmittance and lower solar reflectance (darker color) enhance human visual performance. The proposed workflow provides an experimental procedure, identifies the primary variables and establishes a predictive framework for assessing view clarity of fenestration.
View
Prescribing for the Athlete
Chapter
  • Jan 2022
An overview of management considerations for refractive compensation, protective eyewear, enhancement filters, contact lenses, and refractive surgery for athletes is presented. A task analysis approach with a review of relevant research is highlighted to describe the potential effectiveness of eyewear, filter, contact lens design, and refractive surgery options in various sports.
View
Application of Fourier analysis to the visibility of gratings
Article
Full-text available
  • Aug 1968
1. The contrast thresholds of a variety of grating patterns have been measured over a wide range of spatial frequencies.2. Contrast thresholds for the detection of gratings whose luminance profiles are sine, square, rectangular or saw-tooth waves can be simply related using Fourier theory.3. Over a wide range of spatial frequencies the contrast threshold of a grating is determined only by the amplitude of the fundamental Fourier component of its wave form.4. Gratings of complex wave form cannot be distinguished from sine-wave gratings until their contrast has been raised to a level at which the higher harmonic components reach their independent threshold.5. These findings can be explained by the existence within the nervous system of linearly operating independent mechanisms selectively sensitive to limited ranges of spatial frequencies.
View
A New Test for the Evaluation of Disability Glare
Article
Full-text available
  • Jan 1992
We describe a new glare test that uses low contrast letters and a variable surround glare source. The test is easy to administer clinically and all test targets, luminance levels, glare geometry, and viewing conditions are well controlled. We found the most useful index of disability glare to be the difference in visual acuity scores for the low contrast chart in the no-glare and high-glare conditions and refer to this as the disability glare index (DGI). We tested a group of normal subjects who were divided into younger (age 15 to 41 years) and older (age 50 to 82 years) groups. The mean DGI value for the older group (10.2 +/- 4.8) was significantly higher than that for the younger group (2.3 +/- 1.9). The DGI is a better discriminator between the two groups than either high or low contrast visual acuity. We attribute the significantly higher DGI values in the older group to increased intraocular light scatter. We find DGI is poorly correlated with high contrast visual acuity (r = 0.33). Our findings suggest that this test of disability glare is sensitive to relatively modest changes in the ocular media. It is a potentially useful tool in detection and assessment of subtle media disturbances and in monitoring changes in the ocular media over a period of time.
View
Effect of yellow-tinted lenses on brightness
Article
Full-text available
Magnitude estimates of brightness were obtained for small (5-deg diameter) and large (15 deg × 20 deg) targets viewed through yellow-tinted lenses (ytl’s) and luminance-matched neutral lenses. The results indicate that brightness perception with ytl’s is up to 40% greater than that with neutral lenses when the spatial extent of the stimulus exceeds the fovea. The onset of the enhancement effect is coincident with the chromatic threshold, and its end point is coincident with psychophysical estimates of rod saturation. In a second experiment, brightness estimates were obtained for the ytl’s and neutral lenses during the cone plateau of the dark adaptation curve when rods, but not cones, were desensitized by bleach. The brightness-enhancement effect was negligible. These results confirm the subjective impression that brightness perception is enhanced by ytl’s and indicate that this effect is mediated, in large part, by the contribution of rod signals to the chromatic pathway.
View
Color in sunglass lenses
Article
  • Nov 1969
The extensive literature dealing with color in sunglasses is reviewed. With the exception of therapy in some uncommon illnesses, there is generally no advantage to vision gained by observing through colored, as opposed to neutrally-tinted, lenses. On the other hand, some types of colored lenses have previously been shown to introduce considerable potential hazards in road traffic where traffic signal lights are used. It is concluded that all sunglasses, tinted contact lenses, and motor vehicle windshields should comply with the coloration limits previously proposed. viz., that the “signal visibility factor” (ratio of red to white light transmission) should be between 0.8 and 1.2. and that the excitation purity should not exceed 20%.
View
View
Effect of yellow filter on contrast sensitivity
Article
  • Jul 1984
  • OPHTHAL PHYSL OPT
Abstract Most previous studies have found no visual advantage for the use of yellow filters. This study reports the effect of wearing a long-pass yellow filler on monocular spatial contrast sensitivity under photopic and mesopic conditions. Contrast sensitivity was improved with the yellow filter under photopic conditions but not significantly at most spatial frequencies under mesopic conditions.
View
An investigation into the variation of human contrast sensitivity with age and ocular pathology
Article
  • May 1978
The contrast sensitivities to sine-wave grating stimuli were measured for 36 observers with ages in the range 8 to 67 years. Thirty-one observers had normal, healthy vision while 4 were suffering from diabetic retinopathy and 1 had a early lens opacities and macular degeneration. The younger members of the group with normal vision were less sensitive to low spatial frequencies and the older members were less sensitive to high spatial frequencies than the middle-aged observers. The 5 observers with pathological conditions were less sensitive to most grating stimuli than those with normal vision.
View
Importance of pathological light scatter for visual disability
Article
  • Feb 1986
For healthy eyes intraocular light scatter was investigated several decades ago. For pathological eyes, however, little is known. As clinical test several techniques have been proposed but none has gained general acceptance. A disadvantage of these tests was that quantities were estimated that related only indirectly to the amount of light scatter. We propose a method that gives a direct estimate of the light scatter. We studied patients with cataract, corneal dystrophy, iris and fundus hypopigmentation, etc. A remarkable finding was that visual acuity correlates rather weakly with the amount of scatter. Since, however, the amount of scatter causes a considerable loss of visual function, the results show that for these patients the visual acuity test gives a rather limited impression of their visual handicap. More attention to the problems associated with intraocular light scatter is needed.
View
Color in sunglass Senses
Article
  • Dec 1969
  • Am J Optom Arch Am Acad Optom
The extensive literature dealing with color in sunglasses is reviewed. With the exception of therapy in some uncommon illnesses, there is generally no advantage to vision gained by observing through colored, as opposed to neutrally-tinted, lenses. On the other hand, some types of colored lenses have previously been shown to introduce considerable potential hazards in road traffic where traffic signal lights are used. It is concluded that all sunglasses, tinted contact lenses, and motor vehicle windshields should comply with the coloration limits previously proposed, viz., that the "signal visibility factor" (ratio of red to white light transmission) should be between 0.8 and 1.2, and that the excitation purity should not exceed 20%.
View
View