Why does my sclera look grey?

Discolored sclera: Often, the sclera, or white of the eye can become thinned over time. When that happens, the underlying pigmented tissue called the choroid shows through, giving the sclera a greyish blue appearance. This thinning is usually associated with normal aging changes. Rarely, medical conditions can cause the sclera to thin. If you're not having any other symptoms, there's no concern about this.