The main prism systems in binoculars are roof prisms and porro prisms. Without prisms the image seen through binoculars would be upside down and reversed. Roof prisms provide for a slender, lightweight body but require phase correction coating to provide a clear image. Porro prism binoculars are more economical but still highly effective. Porro prism design also provides for better three dimensional viewing. BaK-4 or BK7 glass is generally used, BaK-4 is of much better quality. Tips: A roof prism design is lighter and more compact but to get the same performance as a porro prism, you will probably pay more for it. Still many of the new high end binoculars are of roof prism design. Here is a picture of the two most common prism layouts

Microscopic quartz-like brighteners that reflect light on the skin's surface to mask wrinkles and imperfections.

Dangling glass pendants used to embellish a lamp. Often of high quality glass, cut and faceted, to reflect and refract the light. Found on many hanging library/parlor lamps, on girandoles, and overlay lamps, to name a few.

Prescribing Information System for Scotland

Provider Registration and International Students Management System