R

Refractive index

The index of refraction is a fundamental optical quantity characterizing any optical environment. For the material of contact lenses the figure of refractive index should be close to the value of…

Refraktometer

It is a computerized device for measuring the refractive defect of the eye.

Retina

The retina is the third and inner coat of the eye which is a light-sensitive layer of tissue. The optics of the eye create an image of the visual world on the retina (through the cornea and lens)…