Final answer:
A scleral crescent is a whitening of the outer layer of the eye that can indicate certain eye conditions and provide information about the shape and position of the eye. It is typically caused by thinning of the sclera.
Step-by-step explanation:
A scleral crescent is a crescent-shaped area of whitening on the sclera, which is the white outer layer of the eye. It is typically caused by thinning of the sclera and can be a sign of certain eye conditions such as myopia (nearsightedness). The presence of a scleral crescent can indicate the shape and position of the eye's components, which can be important in diagnosing and treating vision problems.