What is ametropia?

Ametropia refers to a defect or abnormality in the refractive power of the eye, which leads to issues with how light is focused on the retina. This condition includes various forms of refractive errors, such as myopia (nearsightedness), hyperopia (farsightedness), and astigmatism. Individuals with ametropia often experience blurred vision because the eye does not correctly bend (refract) light rays, resulting in images being out of focus.

The other choices describe different ocular conditions. The absence of the lens pertains to aphakia, which is not the definition of ametropia. Inflammation of the eyelids is known as blepharitis, and is unrelated to the refractive capabilities of the eye. Lastly, a disease that causes increased intraocular pressure refers to glaucoma, which affects vision through pressure rather than refraction. Thus, the understanding of ametropia is specifically linked to its role as a refractive error, making it essential in the context of visual acuity and eye care.