Bioptic Telescopes Meet the Needs of Drivers with
Moderate Visual Acuity Loss
Alex R. Bowers, Doris H. Apfelbaum, and Eli Peli
PURPOSE. Visually impaired people are permitted to use bioptic
telescopes for driving in many states in the United States.
However, it has been suggested that the telescope is used only
to meet the visual acuity criteria for licensure. In this study, a
survey was used to establish the extent to which bioptic
telescopes are used by and meet the driving needs of people
with moderately reduced visual acuity.
METHODS. A cross-sectional survey of a convenience sample of
58 bioptic drivers was administered by telephone interview.
Bioptic telescope usage patterns were quantified with ques-
tions designed specifically for the study. Driving patterns were
quantified by use of the Driving Habits Questionnaire. Subjects
were recruited from four sources across the United States to
ensure a range of bioptic training and driving experience.
RESULTS. The majority (74%) rated the bioptic telescope as very
helpful, and almost all (90%) would continue to use it for
driving, even if it were not required for driving licensure;
however, only 62% reported always wearing the bioptic when
driving. Subjects had relatively unrestricted driving habits, driv-
ing a mean of 222 ? 211 miles per week, and 85% aged ?65
years drove to work. With the exception of driving in rain, in
bright sunlight, and at night, there was little difficulty with
driving in a variety of situations, and levels of driving avoidance
due to vision impairment were low (?10%).
CONCLUSIONS. The bioptic telescope met the (self-reported)
driving needs of the majority of visually impaired drivers in this
survey and was found to be a useful aid for tasks requiring
resolution of detail. (Invest Ophthalmol Vis Sci. 2005;46:
to drive with the aid of a bioptic telescope.1The telescope
provides the visually impaired driver with a magnified view of
objects, such as the text or details of traffic signs, that other-
wise could be resolved only at distances too short for a safe or
timely response. Typically, the telescope is spectacle mounted
at the top of the carrier lens2,3(Fig. 1). Most of the time, the
driver views the road through the carrier lens (with a wide,
uninterrupted field of view), looking intermittently through
the telescope (achieved by a slight downward tilt of the head)
to read road signs, determine the status of traffic lights, or scan
ahead for road hazards.4
hirty-four states in the United States currently permit visu-
ally impaired people with moderately reduced visual acuity
Although driving with the aid of a bioptic telescope is not
permitted in the European Union (EU), there is increasing
interest in the possibility.5In determining whether to allow
bioptic driving, various factors have to be considered including
safety, driving performance, and the social and economic im-
pact of bioptic driving on the life of the visually impaired
person. Advocates of bioptic driving argue that, with appropri-
ate training, the bioptic telescope can be a useful aid for drivers
with reduced visual acuity2,3,6–8; however, some opponents of
bioptic driving9,10are strongly of the opinion that visually
impaired drivers obtain a bioptic telescope purely as a means
to meet the static visual acuity requirement for driving licen-
sure and do not use the device thereafter.
Therefore, it is important to establish the extent to which
bioptic telescopes meet the driving needs of people with
reduced visual acuity. We addressed this question through a
survey of bioptic drivers in which we examined how much the
bioptic telescope compensates for visual acuity impairment
when driving (quantified by bioptic usage patterns) and how
much it enables unrestricted driving (quantified by driving
habits). Previous surveys (using postal questionnaires) have
provided only limited data about bioptic usage patterns and
driving habits of bioptic drivers and were restricted to drivers
from a single state.11–13We included drivers from many states
and used telephone interviews that provide greater opportu-
nity for clarification of responses and control of questionnaire
Visually impaired drivers with recent experience of driving with a
bioptic telescope were recruited from across the United States to
ensure a range of bioptic training and driving experience that was
limited to neither one state nor one training program. The four sources
selected were the Low Vision Clinic of one of the authors (EP) in a
major urban area, the practice of a mobility instructor in a rural area,
the participants in a bioptic driving training program (West Virginia
Low Vision Driving Program), and a convenience sample of responders
to an advertisement placed on the Bioptic Driving Network Web site
Fifty-eight subjects met the inclusion criteria, having driven with a
bioptic for at least 3 months within the previous 3 years. Six subjects
were not currently driving, but had driven within the past 3 years (five
within the past year). All subjects provided informed consent, in
accordance with institutional review board approval, and were assured
of the confidentiality and anonymity of their individual responses. The
study was conducted in accordance with the tenets of the Declaration
For subjects recruited from the Low Vision Clinic and the West
Virginia Program, most of the acuity, diagnosis, and telescope data
were confirmed by review of clinical records. For the remaining sub-
jects we primarily had to rely on their recall, although several of them
referred us to their eye care practitioners who clarified missing or
From the Schepens Eye Research Institute, Harvard Medical
School, Boston, Massachusetts.
Supported in part by National Eye Institute Grant EY12890.
Submitted for publication March 10, 2004; revised July 31 and
September 14, 2004; accepted September 20, 2004.
Disclosure: A.R. Bowers, None; D.H. Apfelbaum, None; E. Peli,
The publication costs of this article were defrayed in part by page
charge payment. This article must therefore be marked “advertise-
ment” in accordance with 18 U.S.C. §1734 solely to indicate this fact.
Corresponding author: Alex R. Bowers, The Schepens Eye Re-
search Institute, 20 Staniford Street, Boston, MA 02114;
Investigative Ophthalmology & Visual Science, January 2005, Vol. 46, No. 1
Copyright © Association for Research in Vision and Ophthalmology
Previous surveys of bioptic11–13and nonbioptic drivers16–19were re-
viewed. Sets of questions relating to bioptic usage patterns and per-
ceived visual difficulty of driving without a bioptic were then devel-
oped (Table 2). Driving habits were quantified using the Driving Habits
Questionnaire (DHQ),16supplemented by a few questions specific to
driving with a bioptic telescope (Table 2). To maintain the psychomet-
ric properties of the DHQ, the additional questions were treated
separately from the original DHQ questions.20The questionnaire also
included questions about background demographic factors, visual acu-
ity and diagnosis, bioptic training received (in-office and on-road), and
years of driving experience, with and without the bioptic. Responses
were primarily sought in a yes/no format, a 5-point scale format (e.g.,
to grade level of difficulty or degree of helpfulness), or a short re-
sponse. (The complete questionnaire is available at www.eri.harvard.
Qualitative validation of the initial questionnaire was performed by
a low-vision rehabilitation practitioner experienced in prescribing
bioptic telescopes, two driving instructors with expertise with the
visually impaired, and a bioptic driver, to assess the questions for
ambiguities, readability, relevance, and face and content validity.20,21
On the basis of this review, questions were selected and modified for
inclusion in the questionnaire. The questionnaire was then tested on
the first 10 subjects recruited into the study. Some extra demographic
questions were added to the questionnaire at the end of the pilot
testing, but the questions relating to bioptic usage, visual difficulty
without the bioptic, and driving habits were not changed. Responses
from the first 10 subjects were therefore included in the data analyses.
The additional demographic questions were administered on a sepa-
rate occasion to these subjects.
The questionnaire was administered by a telephone interview last-
ing 30 to 60 minutes. The majority (91%) of interviews were performed
by one author (DHA), and the rest by another (ARB). Because of
scheduling difficulties, three subjects completed a printed question-
Statistical analyses were performed using the Statistical Package for the
Social Sciences (ver. 11.5; SPSS Science, Chicago, IL). Descriptive
statistics were used to characterize demographics and responses to
questions relating to bioptic usage, visual difficulty without the bioptic,
and driving habits. For all statistical evaluations, ? ? 0.05 was used to
define statistical significance. Differences in demographics between
recruitment groups were analyzed using Kruskal-Wallis tests for rating
scales and non-normal continuous variables, ?2tests for categorical
variables, and one-factor ANOVAs for normally distributed continuous
The relationship between potential independent predictor vari-
ables and dependent measures of (1) bioptic usage (mean bioptic
helpfulness score and percentage of time viewing with the bioptic)
and (2) driving habits (weekly mileage and mean driving difficulty)
were analyzed using step-wise linear regression analyses (with proba-
bility to enter ?0.05 and to exit ?0.1). The independent predictor
variables entered in regression analyses for the two bioptic usage
measures were presence of central field loss, age, participation in
bioptic driving program, years of bioptic driving, and mean visual-
difficulty-without bioptic score. With the exception of mean visual-
difficulty-without bioptic score, which was replaced by the variable
living in a rural location, the same set of independent predictor vari-
ables was also used in multiple regression analyses for the two driving-
Rasch analysis (MiniStep computer program, ver. 3.4222,23) was
used to estimate interval scale measures24for the bioptic helpfulness
scale and the visual-difficulty-without-bioptic scale. For both scales, the
interval scale measure from the Rasch analysis and the mean rating
correlated highly (bioptic helpfulness, r ? 0.98, P ? 0.001; visual
difficulty without bioptic, r ? 0.97, P ? 0.001) and the outcomes of
the statistical analyses were the same irrespective of which of these
summary measures was used. We report only the results of the mean
Age, duration of visual impairment, mean bioptic helpfulness score,
mean difficulty-without-bioptic score, mean driving difficulty, and
weekly mileage were not significantly different from a normal distri-
bution (Kolmogorov-Smirnov test P ? 0.1); all other continuous vari-
ables were significantly different from a normal distribution (P ? 0.05).
type most commonly used by subjects in our survey). (a) The driver
views below the telescope most of the time, (b) viewing only inter-
mittently through the telescope by a downward tilt of the head.
A bioptic telescope used for driving (3.0? Galilean, the
TABLE 1. Summary of Recruitment Sources
(Participation rate)Type of Training Geographic Location
Patients prescribed bioptic telescope at a
Low Vision Clinic in Boston*
14 (100%)† Limited in-office training in bioptic use
(30–60 min); advised to arrange bioptic
driving lessons with specialist instructor
On-road bioptic driving program, including
passenger-in-car, but no behind-the-
wheel, training (?8 h)
On-road bioptic driving program including
classroom, passenger-in-car and behind-
the-wheel training (?100 hours)
Varied, from limited in-office to
participation in on-road bioptic driving
Clients of Certified Orientation and
9 (100%)‡ New Hampshire
Graduates of the West Virginia Low Vision
Driving program 1986–199815
12 (42%)§West Virginia
Advertisement on Bioptic Driving Network
Web site (www.biopticdriving.org)
23 Twelve of the United States;
One province of Canada
* Vision Rehabilitation Service of author (EP).
† Sixteen met the inclusion criteria but 2 were excluded due to poor-quality responses.
‡ Contact details were available for nine clients, all of whom met the inclusion criteria.
§ Fourteen of 33 graduates agreed to participate, 1 did not meet the inclusion criteria, and 1 could not be reached.
IOVS, January 2005, Vol. 46, No. 1
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