Today, eyeglasses are for everyone because it has become an essential fashion accessory. To complete the style that goes perfectly with the dress as well as the personality of the individual it is important to pay attention to eyewear that draws major attention. Wearing a fashionable frame can bring out an entirely new self that will surprise you. No fashion can be complete without proper eye wears or eyeglasses that sport some fashionable lens.
Health awareness is another reason for the popularity of eyewear because the sophisticated lenses used today offer excellent UV protection. Lifestyle changes have increased the outdoor activities of both men and women who now spend more time under the sun and find every reason to sport the choicest eyewear that serves the dual purpose of fashion and health.
The lens must be lightweight and healthy
All lens material must meet two fundamental requirements – it must be lightweight and help to keep eyes healthy by protecting it from harmful UV rays of sunlight. Another factor that is common to all lens material is that is must be high impact resistant or unbreakable. All plastic lenses from CR 39 to polycarbonate, Trivex, high-index plastic, aspheric, photochromic and polarized fulfill these conditions. However, polarized sunglasses are special because of its anti-glare property.
The lens is the only tool that you can use to focus light on the retina in the right manner. While you have enough liberty in choosing the lens material, you do not have an option when it comes to selecting the shape of the lens that can be convex or concave depending on the kind of vision problem you have. People with nearsighted vision will need a concave lens that curves inward and those with farsighted vision will require a convex or outward-curving lens. For those who have problems with the cornea and have astigmatism, only cylindrical lenses can provide proper vision.
As age progresses and you cross forty, your eyes would need more assistance to provide proper vision. Some people need multi-focal lenses that comprise of two or more prescriptions for correction of vision. The bifocals and trifocals come under this category that accommodates more than one lens within a single frame.
Bifocals – This is the most common type of multi-focal lens that you will come across and can make it out easily by looking at the two sections of the lens. The lower part of the lens assists in near vision while the upper portion helps in distance vision. When people cross 40 years the likelihood of presbyopia increases that reduces the ability of the eyes to focus and needs assistance from the bifocal lens.
Trifocals – As the name indicates, this lens comes with three distinct parts with the third section sitting above the bifocal part of the lens. This is useful for viewing objects from very close like viewing the computer screen.
Latest multifocal lenses are available as a seamless lens that does away with the marks of the division of multiple lenses within a single frame.