Refraction of the Eye Spherical

Refraction of the eye is the process of changing the direction of light rays in the eyes due to their refraction on the anterior surface of the lens of the eyeball (anterior lens surface), as well as on the posterior (crystal) surface of the cornea. This process is observed when light passes through the optical system of the eye.

The refraction of the eye is also called the refraction of the optical systems of the eye. The word "optical" refers to the optical media through which light passes. These media are transparent media, including liquids. In this case, the liquid medium of the eye plays the role of an optical system. An optical instrument or optical device can be constructed from transparent optical media by combining them in a certain way in the form of a system of lenses (refraction), mirrors or other transparent media. The transparent environment of the eye is the moisture of the anterior chamber of the eye, the lens and the vitreous body of the eyeball.

There are two types of refraction of the eye - biconvex and biconcave. The eyes of a newborn have biconvex refraction, therefore, after cutting the frenulum of the baby’s tongue during this procedure, there is a significant difference in visual acuity of the left and right eyes for 5 - 7 days. Further, this difference is reduced, the eye begins to adapt to lighting conditions. If physiological anisometropia did not interfere with this and there were no manifestations on the pupil, one could think about the manifestation of heterophoria, since in this case a slight upward tilt of the eye leads to the fact that the central beam is directed below the point of fixation of the eye with large positive far-sighted refractions. 7 – 8% of newborns suffer from hypermetropia greater than +2.0 and +3.0 diopters. But with the development of the eyeballs, the ciliary muscle and lens improve, become larger and better adapted to perform their functions.