The Best Lenses Available for Glasses

Traditional glass lenses have good clarity, scratch resistance and a low price, but they are heavy. Newer materials such as plastic, polycarbonate and high-index glass and plastics overcome this drawback. Choosing the lens material for your glasses can be confusing because of the wide range of options available. This is more so for those with milder prescription power. At higher powers, some of the materials such as plastic are unsuitable, and that naturally means fewer choices. Before you can make a selection, it is important to consider the sphere power and the cylinder power of your eyeglass prescription to know which lens material is best for you.

Polycarbonate Lenses

• Polycarbonate lenses are light and safe, highly impact resistant and also provide complete protection from the UV rays of the sun. This makes them the material of choice for those people who have high prescription power and also those who are actively involved in sports or physical activity. Their lightness and safety means these are the preferred lenses for children's eyewear. Besides general purpose and sports eyewear, polycarbonate lenses are also used in preparing safety glasses.

High-Index Lenses

• High-index plastic and high-index glass lenses are so called because they have a higher index of refraction than regular plastic and glass lenses. These lenses are also thinner than plain plastic and glass lenses, more attractive and also more expensive. Among the two varieties, the high-index plastic lenses are thinner and lighter and provide better protection from UV radiations. Providing an anti-reflective coating gives these lenses a good appearance and improves their anti-glare ability, making them suitable for those who drive at night or spend a lot of time working on a computer. Some of the high-index glass lens varieties are not impact resistant and can shatter quite easily.

Plastic Lenses

• Plastic lenses were developed as an alternative to glass lenses. These have good optical clarity comparable to that of glass, and they are also economical, making them popular. They are much lighter than glass lenses and, therefore, preferred nowadays; however, their thickness increases with prescription power, and they are not useful for people with higher powers. Plastic lenses also tend to get scratches easily, which makes them unsuitable for use with children.

Other Lenses

• Photo chromic lenses are those that come with special chemical coatings to make them darken in bright light. When the intensity of the light reduces, the lenses quickly regain their normal color. Lenses can also receive anti-fog, scratch-resistant and anti-reflective coatings. Of these, anti-reflective coating helps to reduce excessive lens reflections and makes lenses look thinner and more attractive. Another variety of lenses is the aspheric lenses, which don't have a perfect spherical surface but have different degrees of curvature and, therefore, appear thinner. They also allow for equally clear vision whether the wearer is looking directly ahead or sideways.