From time to time questions come up about the interpretation of driving regulations as they pertain to vision. As chair of the POA’s Motor Vehicle Advisory Committee, as well as a member of PennDOT’s Medical Advisory Board, I am happy to research answers to these questions. While these answers are not legally binding, they have been presented to PennDOT’s legal counsel to formulate the best answer possible. Here are two questions which presented recently.
Question: I am writing to you about the phrasing of what PennDOT requires for visual fields. Their letter states, and when you call PennDOT, they say: it has to be a Humphrey visual field. I use the Medmont, which is equivalent to the Humphrey. Is it possible that this regulation for visual fields can be written more clearly so that there is no confusion on the part of rehabilitative staff who may not understand that more than one or two pieces of equipment can measure 120° of visual field legitimately?
Regulation: Under the visual standards relating to the licensure of driving, § 83.3 e states “A person shall have a combined field of vision of at least 120° in the horizontal meridian, excepting the normal blind spots.”
Answer: There is no specific testing instrumentation that is mentioned in the regulation. However, just as we might ask for a Kleenex® rather than a tissue, asking for a Humphrey visual field is simply asking for a visual field which will measure 120° of (contiguous) visual field. In those situations where interpretation of the data is in question, the PennDOT Motor Vehicle Advisory Board members who are familiar with visual fields will be asked to interpret the data. And while we are on the topic of visual fields, there are no waivers for visual fields of less than 120°.
Question: If after cataract surgery a patient has uncorrected VA of 20/20 OD, 20/100 OS, 20/20 OU and corrected VA 20/20 OD, 20/20 OS, 20/20 OU, are they required to wear corrective lenses to drive?
Regulation: Under the visual standards relating to the licensure of driving, § 83.3 a, states “Driving without corrective lenses. A person with visual acuity of 20/40 or better combined vision may drive without corrective lenses.
(1) If a person with visual acuity of 20/40 or better combined vision, however, has visual acuity of less than 20/40 in one eye, the vision in that eye shall be corrected to its best visual acuity.
(2) A person with visual acuity of 20/40 or better combined vision and who has visual acuity of less than 20/40 in one eye, may drive without corrective lenses upon determination by a licensed optometrist or ophthalmologist that the person’s combined vision would not be improved by the use of corrective lenses.
Answer: The language in this section is a bit confusing. The intent of the language is that maximizing visual acuity should be attempted. However, it would be up to the examining eye doctor to determine if improving the vision in the uncorrected 20/100 eye would modify the function, which might determine the ultimate safety of the driver and the community in which that driver will operate a motor vehicle.
If you have any questions for Dr. Freeman concerning motorist vision, please email Kelsey@poaeyes.org with the subject “Motorist Vision.”
