How to perform a Dot Eye Test
Performing a DOT Eye Test as part of the DOT physical eye exam ensures that all commercial vehicle drivers meet the necessary vision standards for safe driving. The test includes three key assessments: visual and binocular acuity, peripheral vision, and color vision. Below is a step-by-step guide for healthcare professionals on how to conduct each part of the test:
Visual acuity test
To assess distance vision and distant visual acuity and clarity, position the driver 10 feet away from the Snellen chart, ensuring the chart is at eye level and well-illuminated. Instruct the driver to cover one eye and read the smallest line of letters they can clearly see. Repeat this process with the other eye and then with both eyes open.
Record the results for each eye, noting if the driver meets the minimum requirement of 20/40 distance vision or better. The driver passes the test if their visual acuity is 20/40 or better in each eye, with or without corrective lenses.
Peripheral vision test
The confrontation test evaluates the driver’s peripheral vision. The examiner holds up a specific number of fingers in the driver's peripheral view and prompts them to identify how many fingers are being held up, which is part of the visual evaluation process.
Position yourself about 2 to 3 feet away from the driver, directly facing them in a quiet, well-lit environment. Ask the driver to cover one eye and focus on your nose or a central point directly in front of them. Extend your arms to the sides and slowly move your fingers or an object from the periphery towards the center of their visual field.
Instruct the driver to indicate when they first see the movement in their peripheral vision. Repeat this for the other eye. To pass the test, the driver must have at least 70 degrees of peripheral vision in each eye.
Color vision test
The color vision test checks for any color blindness, particularly red-green deficiencies. Use 12 Ishihara color test plates in a well-lit room. Present each plate to the driver one at a time and ask them to identify the number or pattern within each plate. Record their responses for all 12 plates.
The driver passes a physical exam if they correctly identify at least 10 of the 12 plates. If the driver incorrectly identifies 3 or more plates, it suggests a potential color vision deficiency, warranting further evaluation.