Certified Ophthalmic Medical Technologist (COMT) Practice Exam

What is the primary role of the autonomic nervous system regarding pupillary response?

1. Regulate vision

2. Control pupil size and reaction

3. Ensure color vision

4. Facilitate eye movement

The correct answer is: Control pupil size and reaction

The primary role of the autonomic nervous system in regards to pupillary response is to control pupil size and reaction. This system consists of two divisions: the sympathetic and the parasympathetic nervous systems, both of which play critical roles in adjusting pupil size. The parasympathetic division is responsible for constricting the pupil in response to bright light, a process known as miosis, while the sympathetic division causes dilation of the pupil, termed mydriasis, in low-light conditions or during the 'fight or flight' response. This dynamic control allows the eyes to regulate the amount of light entering the eye, protecting the retina and contributing to optimal visual function. Other choices, such as regulating vision and ensuring color vision, pertain more directly to the function of the retina and the visual pathways rather than the direct muscular control of the pupil. Likewise, facilitating eye movement primarily involves the extraocular muscles and cranial nerves, not the autonomic nervous system’s role in pupillary control.