Certain visual conditions may impair an individual's ability to drive safely. The attached Vision Conditions and Actions Chart and Glossary of Terms lists and defines common vision conditions and impairments. The chart lists the range of severity, functional impairments, stability of each condition, and actions taken by the department, including restrictions that may need to be imposed on the driving privilege.
The department's vision screening standard is the ability to see 20/40 with both eyes together, with or without corrective lenses. Drivers who fail the vision screening are referred to a vision specialist who must examine the driver and complete a Report of Vision Examination (form DL 62). The driver must submit the completed form DL 62 to the department. Limited term licenses, temporary licenses or extensions are not issued to drivers with low vision who have failed the vision screening until a completed DL 62 has been reviewed and it is determined that the vision condition does not impair the person's ability to drive safely. Individuals with extremely poor vision (visual acuity of 20/200 or worse), may not be scheduled for a drive test.
Following review of the Report of Vision Examination, the driver may be scheduled for a Drive Test or Special Drive Test to determine whether the vision condition impairs the ability to drive or whether the driver can adequately compensate for the vision condition. If the driving test is failed and the condition is severe and the condition cannot be compensated for, a revocation is warranted.
If the department determines from the evidence that the condition could improve and/or the examiner believes driving skills could improve with additional training, restrictions that limit driving exposure, but allow for additional training or practice, can be imposed. Drivers who want to learn to drive or retain their driving privilege may be issued a restricted license or instruction permit for a sufficient length of time suitable to their needs.
An immediate revocation is imposed pursuant to Vehicle Code Section 13953 after an examiner gives a driving test or special driving test to a low-vision driver who has performed dangerously poor and the condition renders the person unsafe to drive. The driver may request a hearing after receiving a notice of suspension or revocation.
Vision Conditions and Actions Chart
The Vision Conditions and Actions chart describes the procedures the department follows when evaluating drivers with possible vision-related driving disabilities. The chart applies to noncommercial Class C and Class M drivers. The Vision Conditions and Actions chart identifies, where appropriate, one or more of the following seven vision functions that may be impaired by the vision condition:
1. Central Vision/Visual Acuity:
When a driver notices something that may be important to his/her driving such as a road sign, hazard, or change in the traffic flow, central vision is used to discern detail, identify, and/or recognize what the driver is looking at. Visual acuity is the finest spatial detail which may be perceived.
The department uses Snellen wall charts to screen driver license applicants for a far visual acuity of no worse than 20/40 in Snellen notation. Snellen wall charts are based on the fact that impaired visual acuity makes it harder to discriminate the fine differences that distinguish one letter from another. Passing this test means that the applicant can read the letters at 20 feet or more that are large enough for a young and healthy observer to read at 40 feet.
Visual acuity impaired by one or more vision conditions can result in the driver failing to read signs and/or recognize hazards in a timely manner.
2. Peripheral Vision:
Normally when you look at something, you center the visual image in the central portion of your visual field. Peripheral or side vision is the field of view that surrounds the central portion of the vision field. In driving, peripheral vision is used in part to detect information that may be important for safe driving. This kind of information includes road signs, appearances of hazards, and changes in the flow of traffic. When the healthy driver notices something important, head and eye movements are used to move the visual image into the central portion of the visual field. In other words, the driver moves his or her head and eyes to look at the object or event of interest.
Peripheral vision is also used in controlling the vehicle. When the driver looks in the rear view mirror, peripheral vision is used to monitor traffic in front of the vehicle. In keeping the vehicle centered in the lane, peripheral vision is used to monitor the lane boundaries.
Peripheral vision impaired by one or more vision conditions can result in the driver failing to react to a hazard coming from the driver's far left or far right, failing to heed a stop light suspended over an intersection, weaving while negotiating a curve, and/or driving too close to parked cars.
3. Night Vision:
The visual ability of two drivers may be about the same during the daylight hours and be markedly different at night. Driving safely at night requires seeing well not only under low illumination, it also requires one to see low contrast objects. Someone wearing dark clothes and crossing the street in front of the driver is much harder to detect at night than during the day because there is much less contrast at night between darkly clothed pedestrians and a dark background.
Night vision impaired by one or more vision conditions can result in the driver at night failing to react to hazards located directly in front of the vehicle, tailgating, and/or failing to steer when necessary because the driver is unable to see low contrast features of the roadway such as its edges and irregularities in the road surface.
4. Glare Resistance and Glare Recovery:
Glare is the disruption of vision due to a veiling luminance (such as the light from the headlights of oncoming traffic at night) being superimposed on the visual image (such as the outline of the car ahead of you).
Glare resistance is the extent to which the driver can still see critical objects and events while facing a steady source of glare such as the setting sun or the light from the headlights on a steady stream of oncoming traffic at night.
Glare recovery is the rapidity with which the driver's vision functioning returns to what it was before the glare was encountered.
Glare resistance/glare recovery impaired by one or more vision conditions can result in the driver being blinded by a glare source and consequently missing curves in the road, striking unobserved pedestrians, and/or crashing into the rear of slow-moving, stalled, or stopped vehicles.
5. Judgment of Distance:
Judgment of distance impaired by one or more vision conditions can result in the driver stopping too short of the limit line or inside the intersection, turning too wide or too short, and/or failing to maintain speed and/or following distance appropriate for prevailing driving conditions.
6. Eye Movements:
Eye movements impaired by one or more vision conditions can result in visual scanning deficiencies. There may be uncontrolled up and down or random scanning rather that side-to-side scanning. There could also be a tendency to look at a specific object too long or continuously look straight ahead. Consequently, the driver may fail to react to hazards and fail to heed traffic signs and signals. Changing lanes could be especially hazardous if the driver spends an excessive amount of time looking to the rear of the vehicle.
7. Visual Perception:
Visual perception is the processing of incoming visual information. Visual perception impaired by one or more vision conditions can result in difficulties with performing several visual tasks at the same time. The driver may have impaired ability to:
- switch attention to important events without interference from distracters or clutter in the visual environment,
- distinguish foreground from background,
- determine the position of other vehicles, signs, and pedestrians relative to self and to each other.
Consequently, the driver may brake and/or stop unexpectedly, maintain inordinately long following distance (to keep from having to react quickly), fail to react to hazards, and/or fail to heed traffic signs and signals.