WASHER ONLY. View All. Spiders are similar to top rings or shade risers in that they are used to reinforce and spread the parts of a lamp or fixture that provide shading. Spiders, however, are generally used to fortify either plastic or glass cylinder-style shades. Though somewhat rare on older lamps, these lamp parts are often found on modern, minimalist-styled light fixtures. We currently offer a brass plated steel spider that is designed for 4â diameter shades or cylinders.
A scleral lens is a specialized contact lens used to manage a variety of eye conditions. It is made of plastic that is clear and rigid, yet allows the eye to breathe, keeping it healthy. A scleral lens is slightly larger than most soft contact lenses and is designed to rest on the white (less sensitive) part of the eye called the sclera. That is why itâs called a scleral lens! This unique design makes the lens very comfortable to wear, all day long.
How Corrective Lenses Work. To make a lens, the first thing you need is a lens blank. Blanks are made in factories and shipped to individual labs to be made into eyeglasses. The raw lens material is poured into molds that form discs about 4 inches in diameter and between 1 and 1 1/2 inches thick. The bottom of the mold forms a spherical curve on the front face. A small segment with a stronger curve may be placed in the mold to form the segment for bifocals or progressive lenses.