Refraktive

Refraktive is an adjective used in optics and ophthalmology to describe phenomena, devices, or measurements that involve refraction—the change in direction of light as it passes between media with different optical densities. The term is often found in Scandinavian languages, where it forms parts of phrases describing refractive properties or errors.

In optics, refraktive concepts include the refractive index of materials, the bending of light at interfaces, and the design of lenses and prisms. Lenses with different refractive powers are used to form or correct images in cameras, telescopes, microscopes, and eyeglasses. Refraction underpins the functioning of optical instruments and is essential in calculating focal lengths and image formation.

In ophthalmology, refraktive error refers to vision problems caused by imperfect refraction in the eye, such as myopia (nearsightedness), hyperopia (farsightedness), and astigmatism. These conditions lead to blurred distance or near vision. Correction methods include spectacles, contact lenses, and refraktive surgeries that alter the corneal shape or the eye’s focusing power, such as LASIK or PRK. The goal is to align light precisely on the retina to restore sharp vision.

The term also appears in discussions of optical design, instrumentation, and vision science, where accurate control of refraction is critical for imaging performance and visual outcomes. See also refraction, refractive error, and refractive surgery.