Which test checks pupillary reaction in patients?

The correct choice is PERRLA, which stands for Pupils Equal, Round, Reactive to Light and Accommodation. This test specifically evaluates the pupillary reaction by assessing three key aspects: the equality of the pupils, their round shape, and their responsiveness to both light stimuli and the process of accommodation (the eye's ability to adjust focus on near objects).

When testing PERRLA, a healthcare provider will shine a light into each eye to observe the direct and consensual responses—where both pupils constrict when light is shone in one eye. Additionally, accommodation is checked by having the patient focus on a distant object and then a near object, noting how the pupils constrict as they focus closer. This comprehensive assessment is vital for determining neurological function and identifying potential issues with the optic and oculomotor nerves.

Other options, while related to eye function and movement, do not focus on assessing pupillary reaction. The cardinal positions of gaze evaluates eye movement and coordination, the oculocephalic reflex assesses brainstem function and eye movement in response to head movement, and extraocular movement tests the function of the extraocular muscles specifically. None of these tests directly measure how the pupils respond to light and accommodation as the PERRLA test