Biomedical Engineering (BME) 3 Practice Test 2026 – Comprehensive All-in-One Guide to Exam Success!

Vitamin A is needed to form the visual pigment rhodopsin in the rods of the retina and to maintain healthy surfaces on the eye. Without it, the eye cannot regenerate rhodopsin after light exposure, so night vision is impaired. If the deficiency continues, the corneal surface becomes dry and keratinized (xerophthalmia), leading to visible changes and potential corneal damage that can progress to irreversible blindness. The other conditions listed—anemia, kidney failure, and diabetes—are not direct outcomes of vitamin A deficiency. Anemia relates to iron, B12, or folate issues; kidney failure involves loss of kidney function; diabetes involves problems with insulin and glucose metabolism.