What is the term for the absence of a natural lens in the eye?

The term for the absence of a natural lens in the eye is "aphakia." This condition typically occurs after cataract surgery when the natural lens is removed but not replaced with an intraocular lens. Aphakia can lead to various visual disturbances, including increased sensitivity to glare and difficulties with focusing, particularly for near vision.

In contrast, presbyopia refers to the age-related loss of near-vision elasticity of the lens, which is not the absence of the lens itself but a reduction in its ability to focus. Myopia, commonly known as nearsightedness, is a refractive error where distant objects appear blurry due to the shape of the eye, while hyperopia, or farsightedness, is where close objects are difficult to see clearly. Understanding these definitions helps emphasize that aphakia specifically denotes the lack of a lens, distinguishing it from other vision conditions that involve the lens but do not indicate its absence.