What term describes the absence of the crystalline lens?

The term that describes the absence of the crystalline lens is "aphakic." When a person is aphakic, it typically indicates that the lens has been removed from the eye, often due to cataract surgery. This condition can affect the way light is focused onto the retina, leading to significant visual changes. Patients who are aphakic may experience increased sensitivity to light and may require special optical correction, such as glasses or contact lenses, to improve their visual acuity.

The other terms in the question refer to different visual conditions. For example, hyperopia (farsightedness) and myopia (nearsightedness) describe refractive errors related to how light is focused due to the shape of the eyeball or cornea. Presbyopia is an age-related condition characterized by the lens's loss of flexibility, making it difficult to see close objects. While all of these terms relate to vision and the eye, only "aphakic" specifically refers to the absence of the crystalline lens.