Anophthalmia and microfthalmia are often used interchangeably. Microphthalmia is a condition where one or both eyes are abnormally small, while anophthalmia is the absence of one or both eyes. These rare conditions develop during pregnancy and can be associated with other birth defects.

Causes of these conditions can be genetic mutations and abnormal chromosomes. Researchers also believe that environmental factors, such as exposure to X-rays, chemicals, drugs, pesticides, toxins, radiation, or viruses, increase the risk of anophthalmia and microfthalmia, but research is inconclusive. Sometimes the cause cannot be determined in an individual patient.

There is no treatment for severe anophthalmia or microfthalmia that will create a new eye or restore vision. However, some less severe forms of microfthalmia may benefit from medical or surgical treatment. In almost all cases, improvements to a child's appearance are possible. In children, a prosthetic (artificial) eye can be applied for cosmetic purposes and to promote the growth of the socket. A newborn with anophthalmia or microfthalmia will need to visit a variety of eye care professionals, including those specializing in pediatrics, vitreoretinal disease, orbital and oculoplastic surgery, ophthalmic genetics, and prosthetic devices for the eye. Any specialist can provide education and possible treatments that result in the best care for the child and family. The prosthetic eye specialist will create conformers, plastic structures that help support the face and stimulate the eye socket to grow. As the face develops, new conformers will have to be created. A child with anophthalmia may need to use expanders in addition to conformers to further enlarge the eye socket. Once the face is fully developed, prosthetic eyes can be made and placed. Prosthetic eyes will not restore vision.