Elements of the eyeball reflect the object on the retina, which converts the electromagnetic waves to the nerve. This signal is
interpreted by the corresponding brain centers. Not only do the light has an impact on dynamic functions, but also on the optical properties of the eye. This occurs both through photochemical and sensory systems. Photochemical changes involve both direct and indirect formation of chemical reactions in the tissues of the optical components of the eye. UV and IR radiation causes
ataracts. In addition, UV radiation contributes to the formation of pterygium and climatic droplet keratopathy. Sensory changes modify the geometry of the eyeball and mainly axial length, in response of a brain to the quality and characteristics of the retinal image of the eye.