Infants born with orbital tissue missing from one or both eyes, they are diagnosed with Anophthalmos. The condition is rare with only 0.18 cases per 10,000 births. At the time of birth, the infant often has an eyelid, but the eye tissue (or eye ball) normally filling in the socket is missing. The condition occurs in utero. Treatment is needed for infants born with Anophthalmos to stretch the orbital socket for prosthesis and / or to prevent severe deformation of the face with growth.

Microphthalmos is more common than Anophthalmos. Microphthalmos presents with a smaller than average mass of orbital tissue. Removal of the tissue may be required before treatment can begin and a prosthesis can be fitted. Treatments for both conditions require stretching the socket. This can be accomplished with an orbital conformer or inflatable conformer.

Causes of Anophthalmos / Microphthalmos include chromosome deletion, trisomy 13-15, maternal infections while pregnant and side effect of other syndrome such as Goldenhar or Hallermann-Streiff).