Which condition causes poor vision at night or in dim lighting?

Which condition causes poor vision at night or in dim lighting?

• A. Night Blindness
• B. Pterygium
• C. Subconjunctival Hemmorhage
• D. Dry Eye Syndrome

Answer: (A)

Night vision relies on the rods in the retina, which handle vision in dim light. When someone has trouble seeing in the dark or in low lighting, this is called night blindness (nyctalopia). It happens when rod function is impaired or rhodopsin—the pigment rods use to detect light—is not regenerated properly, as can occur with vitamin A deficiency or certain retinal diseases. The other conditions describe eye surface or conjunctival issues that affect vision in different ways but not specifically night-time vision. A pterygium is a growth on the conjunctiva that can cause irritation or astigmatism and glare; a subconjunctival hemorrhage is bleeding under the conjunctiva that usually doesn’t change vision; and dry eye syndrome causes fluctuating vision due to tear film instability, not a primary problem with low-light adaptation.

Night vision relies on the rods in the retina, which handle vision in dim light. When someone has trouble seeing in the dark or in low lighting, this is called night blindness (nyctalopia). It happens when rod function is impaired or rhodopsin—the pigment rods use to detect light—is not regenerated properly, as can occur with vitamin A deficiency or certain retinal diseases.

The other conditions describe eye surface or conjunctival issues that affect vision in different ways but not specifically night-time vision. A pterygium is a growth on the conjunctiva that can cause irritation or astigmatism and glare; a subconjunctival hemorrhage is bleeding under the conjunctiva that usually doesn’t change vision; and dry eye syndrome causes fluctuating vision due to tear film instability, not a primary problem with low-light adaptation.