Marcus Gunn Reflex

The Marcus Gunn Reflex is an eye condition observed during a medical exam where the affected eye does not react as expected to light. When light is shone in the good eye, both pupils should constrict. However, if light is directed at the affected eye, it may appear to dilate or fail to constrict properly. This reflex indicates a problem with the eye's nerve pathways, often associated with conditions like optic nerve damage or retinal issues. Essentially, it demonstrates how the brain and eyes communicate and helps doctors diagnose underlying vision problems.