Eye standards for a second-class airman medical certificate are:
(a) Distant visual acuity of 20/20 or better in each eye separately,
with or without corrective lenses. If corrective lenses (spectacles or
contact lenses) are necessary for 20/20 vision, the person may be eligible
only on the condition that corrective lenses are worn while exercising the
privileges of an airman certificate.
(b) Near vision of 20/40 or better, Snellen equivalent, at 16 inches in
each eye separately, with or without corrective lenses. If age 50 or
older, near vision of 20/40 or better, Snellen equivalent, at both 16
inches and 32 inches in each eye separately, with or without corrective
lenses.
(c) Ability to perceive those colors necessary for the safe performance
of airman duties.
(d) Normal fields of vision.
(e) No acute or chronic pathological condition of either eye or adnexa
that interferes with the proper function of an eye, that may reasonably be
expected to progress to that degree, or that may reasonably be expected to
be aggravated by flying.
(f) Bifoveal fixation and vergence-phoria relationship sufficient to
prevent a break in fusion under conditions that may reasonably be expected
to occur in performing airman duties. Tests for the factors named in this
paragraph are not required except for persons found to have more than 1
prism diopter of hyperphoria, 6 prism diopters of esophoria, or 6 prism
diopters of exophoria. If any of these values are exceeded, the Federal
Air Surgeon may require the person to be examined by a qualified eye
specialist to determine if there is bifoveal fixation and an adequate
vergence-phoria relationship. However, if otherwise eligible, the person
is issued a medical certificate pending the results of the examination.