daianna's blog

In the past the lenses of prescription eyeglasses are usually thick and heavy, especially those with strong prescription. But now because of high index lenses, lenses are much thicker and lighter.

The new advancement in the lens manufacture technology is the use of ultra high index material. These materials provide the ability to manufacture very thin and flat prescription lenses for people who wish to be at the height of fashion. People with higher prescriptions like +/-10.00D can make use of ultra high index lenses for a very thin and flat eyeglass. The cost of the lenses increases with the decrease in their thickness. Thinner and flatter lenses are made out of high index material as these lenses have flat front curves. The aspheric curves deployed in these lenses provide distortion free clear vision with flat and thin structure.

The high index lenses have certain advantages and disadvantages over conventional lenses. On the positive side, these lenses are very flat and thin, giving the wearer the look of an elegant chic. They are also shatter proof and are robust. They can be curved and fitted to frames to give a trendy look. On the negative side, the eyeglasses that use high index lenses are expensive. A separate scratch resistant coating is to be given on the lenses to prevent scratches.

With the great advancements in the glass manufacture technology lenses are now made using different materials. Thin lenses are now manufactured using high index plastic material. They have good optical quality and they are of light weight compared to the conventional glass and plastic lenses. The prescription lens requires two properties - the refractive index of the lens and the curvature. When the lens has a higher refractive index, it can bend more light and thus curvature can be minimum leading to a thin lens.

High index lenses are now made using glass or plastic depending on the needs. When the material has high index of refraction, it will be dense and hence lesser material is used in making lens leading to a thinner one. The higher the refractive index of the material, the thinner is the lens made out of it.

High index lenses are more expensive. But they are thinner so look more elegant. At the same time, they are lighter, so put less pressure to our eyes and nose. They are the best choice for people who need strong prescription eyeglasses.