Visual acuity test results
The Snellen eye test results use 20 feet as the norm, represented by the numerator
in the Snellen test result. The number of the last line of type the driver read
accurately is recorded as the denominator in the Snellen test result.
The minimum qualification requirement is distant visual acuity of at least 20/40
in each eye and distant binocular acuity of at least 20/40.
If a test other than the Snellen is used to test visual acuity, the test results
should be recorded in Snellen-equivalent values.