You can choose your spectacle lenses according to your lifestyle and budget. Glass is the conventional material used in making lenses. However, plastic lenses are gaining popularity in recent times owing to their lightness. Polycarbonate lens are preferable for people engaged in excessive physical activities, especially sports persons and children.
People suffering from shortsightedness are prescribed concave lenses, whereas convex lens are used for correcting long-sightedness. The center of concave lenses is thinner than convex lenses. On the other hand, edges of concave lens are thicker than the edges of convex lens. The weight and thickness of lenses increases with increase in the power of the lenses.
If you are prescribed high-powered lenses, the conventional glass lenses could appear unattractive with their high weight. To resolve this problem, you can opt for aspheric lenses. These lenses are made of high-index materials, which make the lenses lightweight and thin. High-index materials are used in making lenses for correcting shortsightedness.
In case of lenses for correcting long-sightedness, aspheric designs, which shifts the center of curvature of the lens to the edge from the center, reduces the amount of materials required to manufacture the lens. Besides being light weighted, Aspheric lenses increases the field of vision and reduces the prismatic effect experienced in conventional lenses.
Bifocal and Varifocal lenses
Bifocal lenses are prescribed for individuals suffering from presbyopia, who need correction for both long and shortsightedness. Conventional bifocal lenses have a line separating the upper and the lower parts of the lens. If you want to eliminate the dividing line visible in bifocal lenses, opt for varifocal lenses. In these lenses the power changes gradually enabling the wearer to see all distances clearly.
To eliminate reflection of light, spectacle lenses with anti reflection coating are helpful. This is beneficial especially to people who work in front of computers for a long time, or drive in the night. To reduce scratches, lenses with scratch resistant coating could be used. Photocromic lenses protect the eyes from bright light. Multicoated lenses perform variety of functions, including preventing reflection, scratches and protect the eyes from UV light.