What are the Types of Eye Lenses?
Dr Alok B S
Kalyan nagar, Bengaluru Jan 28, 2019
Earlier all eyeglasses were made up of glass. Glass lenses offer exceptional optics, but they are heavy and break easily and can also cause serious harm to the eye. Today most of the eyeglasses are made up of high-tech plastics. They are lighter and don’t break easily and protects your eye from UV light. They are also scratch resistant.
You will need a concave lens of you are near-sighted and a convex lens if you are farsighted. If you have astigmatism or your cornea is shaped wrong then you need lenses shaped cylindrically.
What are Multifocal Eyeglass Lenses?
Bifocals: These glasses are split into two sections. The upper part helps with distance vision and the lower half help with near vision. These leses are lighter, thinner, and more atteactive. Modern bifocal eyeglass lenses are popular and called as flat-top (FT) or straight-top (ST) design.
Trifocals: These have three sections, and the third section is above the bifocal portion of the lens. It is used to look at the objects which are at the arms distance. These lenses are perfect for seeing your speedometer, for computer use, and other dashboard gauges while driving. Trifocals eyelenses are generally preferred to older people who age is over 50.
Types of Lenses
Like technology, lenses are also advanced. Previously, the lenses were made up of only glasses but in the present, most lenses are made up of high-tech plastics.
Polycarbonate: These are scratch and impact resistant lenses, and they are perfect for kids wo are tough on their glasses, for those who play sports, or for people who work in a environment where eyeglasses can easily break or damage. They also have built-in UV protection.
Trivex: These are prepared from an unique and new plastic which is similar to polycarbonate lenses. Glasses made from this plastic are lightweight, thin, and impact resistant. Experts also believe that these may correct the vision of the eye for few people.
High-index plastic: These lenses are lighter and thinner than the old lenses.
Aspheric: These lenses have many degrees of curvature which means they can be flatter and thinner so that it can be used for a much larger portion of the surface.
Photochromic: They changes from clear to tint in sunlight. If you have photochromic lenses, you no longer need a sunglasses to protect your eyes from harmful UV rays. Thses are available in both, plastic and glass.
Polarized sunglasses: These lenses reduce glare from a surface like water, so they are great for sports and driving.