(1) The cornea and the crystalline lens refract light that enters the eye.(2) Metamaterial research is an emerging field that uses manmade substances to alter the way materials refract light or electromagnetic radiation.(3) They cut glass, they refract light into perfect hearts-and-arrows, and they have superlative fire and brilliance.(4) Ideally we would like to refract the shadow ray too, but mathematically this is a much more difficult problem to solve.(5) The cornea and lens refract the incoming light rays to focus them on the retina at the back of the eye.(6) Spectacles and contact lenses refract the light before it enters the eye, helping the eye to focus objects sharply.(7) Color is important: one sees the reds, tans and browns of skin color, the blue of water and the wavy white lines of light refracted through the water.(8) Not only is the roof above them made of glass, it is also filled with water, further refracting the light received in the public spaces below.(9) In De Natura Locorum he gives a diagram which shows light being refracted by a spherical glass container full of water.(10) The rays were detected by a calcium sulfide thread that glowed slightly in the dark when the rays were refracted through a 60-degree angle prism of aluminum.(11) The regional variation of ocean depth acts as a lens to refract the waves, just as a lens refracts light.(12) Sparkling glass goblets and mugs refracted the light just as the silver reflected it.(13) It acted like a prism on the setting sunlight striking it, refracting the light in much the same way as a crystal would.(14) The image passes through the lens, which further refracts the light through its anterior and posterior curvatures.(15) The hotter, denser air refracts the light coming from the horizon and the viewer sees an image of the sky near the horizon.(16) A light ray is refracted when it passes from one medium to another at an angle and its speed changes.