Eyeglasses or spectacles, help in rectifying flawed vision. Eyeglasses are generally made up of a pair of lenses fixed to a frame to keep them in place before the eyes. The earliest tool of this type was in all probability invented by Roger Bacon in the 13th century even though comparable devices are thought to have been present in ancient times in China and in the Mediterranean societies. Initial types were rough and inelegant and were not enhanced until the 18th century when the grinding of lenses was first related to the principles of light refraction.
Eyeglasses assist in rectifying refractive flaws and they fulfill this task by augmenting or reducing focusing power to the eye’s cornea and lens.
Eyeglasses, also popularly known as spectacles, is the most widespread type of eyewear utilized to rectify or enhance several kinds of difficulties linked to vision. It consists of a frame that keeps in place two pieces of glass or plastic, which have been transformed into lenses to rectify refractive flaws. Refractive flaws can include nearsightedness or myopia (having problems seeing objects at a distance, farsightedness or hyperopia (having troubles seeing objects that are near), and astigmatism (haziness of vision because of an unevenly shaped cornea). Eyeglasses perform this function by enhancing or diminishing focusing intensity to the eye’s cornea and lens.
Kinds of Eyeglass Lenses
The kinds of lenses utilized in eyeglasses is related to the type of vision trouble the person is experiencing. It includes concave lenses, convex lenses and cylindrical lenses.
- Concave lenses – Such type of lenses are most thin in the middle and utilized for rectifying nearsightedness (myopia).
- Convex Lenses – Such type of lenses are most thick in the middle like a magnifying glass. They are employed for rectifying farsightedness.
- Cylindrical Lenses – Such types of lenses are curved to a greater extent in one direction than in the other and are frequently made use to rectify astigmatism.
Selecting the Right Eyeglasses
One should be extremely careful while selecting the right type of eyeglasses for children since eyeglasses play a vital role in rectifying defects related to vision. Improper selection is likely to have an adverse impact on the vision of children. While selecting eyeglasses it is always advisable to keep in mind the requirement of the concerned individual. Shatterproof and impact resistant lenses should be preferred for individuals who take part in sport activities.
It is favourable to use lenses with scratch resistant covering. A spring-loaded frame has little chances of bending and is also a suitable option. Silicon nose pads provide added comfort since they prevent the glasses from sliding. Straps can also be utilized for keeping the glasses in position.