Eyepieces & Eyepiece Cups
An eye piece is the part of the camera you look through to find your image. An eyepiece cup, which usually has a rubberized outer frame for you to rest your eye on, is attached to the eyepiece for comfort. The cup will also keep stray light from entering the viewfinder and washing out contrast. The best type of eye pieces to use are the anti fog variety.
These eyepieces use specially treated glass which will prevent the eyepiece from fogging or from condensation forming on them. A good eyepiece should also be designed for use in warm and humid or cold weather. This is when fogging is most likely to occur on the eyepiece. Some camera models offer interchangeable and replaceable eyepieces.
Eyepieces usually range in price from about $25 to $40.