Introduction
The eyes need protection to keep them healthy. That is why a protective coating is included on the lens. There are several types of coatings which include:
- Anti-reflective coatings which have fewer reflections off the surface of the eyeglass. The result is that the wearer has an improved appearance and the presence of more effective eye contact with others. Other advantages include reduced eye strain, reduced glare and reflections, improved contrast, sensitivity and visual acuity.
- Some eyeglasses are coated with material which protects against UV light. Some plastic lenses come with inbuilt UV protection.
- Protection from prescription sunglasses with UV protection.
- Photochromic lenses suitable for both the indoors and outdoors. These lenses are made of a tint that changes according to the amount of light present. When there is sunlight, the darker tint is used while the lighter tint works when one is indoors. However, photochromic lenses do not work well in all environments. For instance, in a car or airplane, the windows may block the UV light that triggers a change in the tint. It takes time for the tint of the lens to adjust from dark to light.
