Final answer:
The FMCSA requires a Medical Examiner to evaluate pupil reactivity, which includes the pupillary light reflex. The corneal reflex and accommodation-convergence reflex are also important to assess for safe driving ability.
Step-by-step explanation:
According to FMCSA regulations, the Medical Examiner (ME) must evaluate a driver's pupil reactivity when examining their eyes. This involves assessing the pupillary light reflex, which is a response involving sensory input through the optic nerve and motor response through the oculomotor nerve.
This reflex causes the pupils to constrict under bright lighting conditions to limit the amount of light falling on the retina. Another essential ocular examination includes the corneal reflex, a protective response causing blinking when the cornea is stimulated. This reflex involves the trigeminal nerve as the sensory pathway and the facial nerve for the motor response. Lastly, the ME might assess convergence and accommodation through the accommodation-convergence reflex, controlling the eye's ability to focus on near objects, vital for drivers who need to quickly shift focus from the road to their instrument panel.