Which of the following is NOT checked during a vision examination?

In a standard vision examination, certain key aspects of visual function and eye health are assessed. PERRLA, which stands for Pupils Equal, Round, Reactive to Light, and Accommodation, is a critical examination component that checks the neurological function relative to the pupils. Nystagmus, the involuntary movement of the eyes, is also monitored, as it can indicate various neurological or vestibular disorders. Exophthalmos, the protrusion of the eyeball, is evaluated for signs of thyroid disease or other medical concerns related to the eyes.

Color blindness, while it may be screened in specific settings, is typically not a part of a routine vision examination focused on assessing basic visual acuity and eye health. It normally requires specialized tests to determine specific types of color vision deficiencies, which are not standard in general eye exams unless there is a specific concern about color perception. Therefore, the correct response identifies color blindness as the aspect not routinely checked in a vision examination, distinguishing it from the more common evaluations of pupillary response, eye movements, and physical eye condition.