Q13: Congenital malformations of anterior segment of eye

Q13.5: Blue sclera

The sclera forms the outer, white sheath for the eye. It is made of firm connective tissue and it gives the eye its spherical shape. At the front of the eye the sclera transitions into the transparent cornea.

The sclera can look blueish instead of white if it is unusually thin. In a case like this, the choroid blood vessels can be seen gleaming blue. Your sclera is unusually thin because the connective tissue has changed. There are various disorders that involve changes to the connective tissue in the sclera. These include brittle bone disease, Ehlers-Danlos syndrome, and Turner syndrome, for example.

The defect of the sclera can be hereditary. Other family members can also be affected by a hereditary disorder.