What word denotes a manifest or observable deviation of an eye from its normal alignment?

The term that denotes a manifest or observable deviation of an eye from its normal alignment is 'tropia.' When one of the eyes is misaligned, such as turning inward, outward, upward, or downward, it is referred to as tropia. This misalignment can be visually apparent and can affect vision, leading to difficulties in coordination between the two eyes.

In contrast, phoria refers to a latent deviation that is not observable unless the binocular vision is disrupted, meaning it's not seen during normal visual tasks. Strabismus is a broader term that encompasses both tropia and phoria but is often used to describe conditions where misalignment is present. Diplopia describes the condition of double vision, which can occur as a result of misalignment but does not directly indicate the misalignment itself. Understanding these definitions clarifies the specific meaning of tropia in the context of eye alignment.