Aphakia is the absence of the lens of the eye, due to surgical removal, such as in cataract surgery, a perforating wound or ulcer, or congenital anomaly. It causes a loss of ability to maintain focus (accommodation), high degree of farsightedness (hyperopia), and a deep anterior chamber. Complications include detachment of the vitreous or retina, and glaucoma. Babies are rarely born with aphakia. Occurrence most often results from surgery to remove a congenital cataract. Congenital cataracts usually develop as a result of infection of the fetus or genetic reasons. It is often difficult to identify the exact cause of these cataracts, especially if only one eye is affected.