A property of a material that changes the speed of light, computed as the ratio of the speed of light in a vacuum to the speed of light through the material. When light travels at an angle between two ...

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 ...

The Brix scale, derived from the refractive index of a solution at 20 degrees Celsius (68 Fahrenheit), is widely known. Originally, it was established by determining the weight percentage of sucrose ...

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 ...

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

Researchers at Harvard’s John A. Paulson School of Engineering and Applied Sciences have announced the first on-chip metamaterial with a refractive index of zero — meaning the phase of light can ...