The Unique Kinds Of Eyeglasses
Eyeglasses are comprised of frames that contain lenses and are placed before eyes for the sake of vision correction or protection. Safety glasses provide protection from radiation, light, or flying objects. Sunglasses improve vision while in brightly lit environments and can reduce damage from ultraviolet light. Other glasses help view visual information or are worn simply for aesthetic reasons.
Glasses come with padded supports to rest on the nose bridge and have sides to rest on the ears. The most popular lenses are the CR-39 type. These block infrared and ultraviolet radiation, have low dispersion, are scratch resistant, and weigh little.
There are several types of eyeglasses. Examples are extreme magnification, progressive, trifocal, bifocal, reading, 3D, sun, safety, and corrective glasses. Corrective glasses have lenses that adjust focal lengths to improve astigmatism, farsightedness, and nearsightedness.
Nearsightedness is when objects look blurry that are far away but close Women Sunglasses objects are clear. Lenses worn by people with this condition are concave in shape. Farsightedness is corrected by using convex lenses that help objects that are close appear less blurry. Cylindrical shaped lenses are used to improve astigmatism, which otherwise impairs the pathway of light to the retina. Corrective forms of eyeglasses improve individuals sight and minimize side effects, such as headaches.
Glasses for safety are made using a plastic lens that is shatter resistant. This prevents eyes from damage by flying debris. There is great diversity in how much protection different products offer. Some that are meant for use in the medical field shield against fluid splatter. Others worn in factories must prevent damage from flying wood, metal, or sawdust. Therefore the factory glasses will need a stronger lens and to have more shielding than ones for medical professionals. The lenses of either can be modified to be corrective.
Sunglass lenses can be prescription or darkened. Darkening provides extra protection against light damage, including damage from UV rays. Photochromatic type lenses are another option. These darken when UV light is present. Light polarization is another possibility, which helps with glare elimination. This is very beneficial for pilots, who could otherwise become blinded while in flight.
Yellow shaded lenses increase color contrast and improve depth perception. This is a great advantage at dusk but can be harmful if worn at night. Sometimes these are not worn for their functional uses but because they are considered aesthetically pleasing. Individuals who are blind may also wear sunglasses to hide their eyes.
3D glasses trick the eyes into seeing in three dimensions when looking at only two. This is achieved by using a blue lens and a red one. Another option is to have one that is polarized vertically and another that is polarized horizontally. The trick is to have one eye take in different information from the other.
Eyeglasses come in various sizes, shapes, and uses. They can be worn to correct sight and protect, or simply as a statement of fashion. Even 3D versions exist and are used to see in three dimensions for entertainment purposes.
Author: sabisoodartThis author has published 120 articles so far.