What is aphakia?

What is aphakia?

• A. Congenital absence of a lens
• B. Absence of iris
• C. Absence of vitreous
• D. Absence of cornea

Answer: (A)

Aphakia is the absence of the crystalline lens in the eye. The lens provides most of the eye’s refractive power and also enables accommodation. When the lens is missing, the eye loses its main focusing element, so images tend to be formed behind the retina, causing a very strong hyperopic (farsighted) error and loss of near vision. This condition can be congenital, but more commonly it occurs after surgical removal of the lens during cataract surgery. Correction typically involves very strong plus lenses or contact lenses to replace the lens’s refractive power, and sometimes an intraocular lens implant is used. Absence of the iris would be a different condition (aniridia), absence of the vitreous is not the term used for a missing lens, and absence of the cornea leads to a different, severe visual problem requiring corneal transplantation. So the term that matches “absence of a lens” is aphakia.

Aphakia is the absence of the crystalline lens in the eye. The lens provides most of the eye’s refractive power and also enables accommodation. When the lens is missing, the eye loses its main focusing element, so images tend to be formed behind the retina, causing a very strong hyperopic (farsighted) error and loss of near vision. This condition can be congenital, but more commonly it occurs after surgical removal of the lens during cataract surgery. Correction typically involves very strong plus lenses or contact lenses to replace the lens’s refractive power, and sometimes an intraocular lens implant is used.

Absence of the iris would be a different condition (aniridia), absence of the vitreous is not the term used for a missing lens, and absence of the cornea leads to a different, severe visual problem requiring corneal transplantation. So the term that matches “absence of a lens” is aphakia.