The amblyoscope is an opthalmic device for measuring binocular vision and treating amblyopia (lazy eye). Amlyopia occurs in young children when one eye has weaker vision than the other. In the first few years of childhood, the brain is developing neural pathways as it learns to "see." At this stage, if one eye dominates the other, those pathways remain underdeveloped for the weaker eye. It is important to identify the problem early and treat it while the brain is still developing, but the condition is not always obvious.

The amblyoscope was invented in 1895 by Claud Alley Worth of London and refined by Nelson Black, who added the vertical adjustment.