What feature is typical of a horse exhibiting the "wall eye" condition?

A horse exhibiting the "wall eye" condition typically has a blue eye. This condition, known scientifically as "blue sclera," occurs when there is a partial or complete lack of pigmentation in the eye, leading to a blue appearance. This can result from various factors, including genetics or certain health conditions that affect pigment production. In horses, blue eyes are often more noticeable in certain breeds and can give the horse a distinctive look that might be associated with the "wall eye" condition.

While other colors of eyes can certainly be found in horses, the presence of a blue eye is specifically linked to the wall eye condition, making it the correct choice.