Which of the following is a cause of ocular-origin blindness?

• A. Trauma
• B. CNS disease
• C. Hepatic encephalopathy
• D. Hyperammonemia

Answer: (A)

Ocular-origin blindness means the eye itself is the source of vision loss. Trauma directly injures ocular structures such as the cornea, lens, retina, or optic nerve, and can cause permanent blindness from those injuries. In contrast, a brain or CNS problem disrupts visual processing, so the eye and its anterior structures may look normal on exam even though vision is lost. Hepatic encephalopathy and hyperammonemia produce generalized brain dysfunction rather than primary eye disease, so they typically cause blindness only through central, not ocular, pathology. Thus, trauma is the direct cause of ocular-origin blindness.