What is diplopia?

Diplopia refers to the experience of seeing two images of a single object, commonly known as double vision. This condition can arise from a variety of underlying factors, including issues with eye alignment, muscle control, or neurological conditions. The perception of double vision can be horizontal, vertical, or diagonal, and it may affect one eye or both, depending on the cause.

In understanding the other options, night blindness specifically describes a difficulty seeing in low light conditions, which is distinct from the visual disturbance caused by diplopia. Loss of peripheral vision involves a reduction in the ability to see objects outside of one's direct line of sight, while cloudiness of the lens pertains to cataracts, which obscure clear vision but do not specifically relate to seeing double. Thus, the correct definition of diplopia as double vision highlights a unique visual phenomenon that is distinct from these other conditions.