A refraction test is usually given as part of a routine eye examination. It may also be called a vision test. This test tells your eye doctor exactly what prescription you need in your glasses or ...

Researchers used ultrasonography, phakometry, keratometry, pachymetry, interferometry, anterior segment optical coherence tomography and high-resolution MRI on the right eyes of 91 adults, according ...

Recent experiments that demonstrate the negative refraction of light could bring a heated scientific debate to a close, and give negative-index materials a positive future Figure 1: Negative-index ...

When a ray of light is incident at normal incidence, (at right angles), to the surface between two optical materials, the ray travels in a straight line. When the ray is incident at any other angle, ...

The speed of light is determined by the medium (material) through which the light is travelling. Light travels faster in a vacuum than it does in any other medium. Light changes speed as it passes ...