Which symptom is most characteristic of diplopia?

• A. Itching
• B. Hearing loss
• C. Double vision
• D. Redness

Answer: (C)

Seeing two images of a single object is the defining feature of diplopia. This occurs when the eyes don’t align properly, so the brain receives two separate visual inputs instead of a single fused image. That’s why double vision is the hallmark symptom. By contrast, itching suggests surface irritation or allergy, hearing loss points to an ear-related issue, and redness indicates conjunctival inflammation—none of which describe diplopia. A quick clinical check is to have the patient cover one eye: if the double vision goes away, it’s binocular diplopia due to misalignment; if it persists with one eye closed, the problem is monocular and related to the eye itself.