Acquired color vision defects are often monocular.

• A. Acquired color vision defects are often monocular.
• B. Acquired color vision defects are always binocular.
• C. Acquired color vision defects cannot be detected with color tests.
• D. Acquired color vision defects occur only in youth.

Answer: (A)

Understanding how color vision loss presents helps distinguish acquired from congenital defects. Congenital color vision defects are usually present in both eyes because the underlying issue affects the color vision system globally. Acquired defects arise from diseases or injuries that can hit one eye at a time—such as optic nerve damage or localized retinal disease—so testing each eye separately often reveals a defect in only one eye. When both eyes are tested together, the functioning eye can compensate, making the problem appear monocular rather than binocular. That’s why saying acquired color vision defects are often monocular is the best fit. The other statements don’t hold: defects can be detected with color tests, they’re not limited to youth, and they aren’t necessarily always binocular.