For this reason, known personalities from presidents to screen actors employ the services not only of the best ophthalmologists (optometrists/opticians) but also of the best eyeglass designers. A good ophthalmologist should have an excellent grasp of how tints can affect desired lens' optical properties, a skill that must be complemented by an eyeglass designer's dexterity on coming up with the most appropriate style and design that suits a person.
It would be best for you to have a basic understanding of how tints are incorporated to the bare colorless lens before deciding which to purchase. Although in most cases, it would appear that tints are applied as a coating on the lens (like painting on a wall), they could have been either laminated on the lens surface or embedded just underneath the surface of the lens.
Needless to say, these types of tinting make the eyeglasses color easily fade over time through water and chemical corruption and therefore may not be a good choice. More expensive eyeglasses have tints that are incorporated and homogeneously mixed into the pure raw glass. This particular understanding about corrective eyeglasses shading plays an important role in choosing the right eyeglasses for they matter as much as the type of material the lens are made of.
What are the available eyeglass tints? Interestingly enough, eyeglass tints perform other functions apart from their visual corrective properties.
One cannot overlook the fashion tints which are meant to accentuate the beauty of the wearer's eyes. Eyeglasses, which were invented in the late 1200's to correct impaired vision, are now important fashion accessories worn by famous celebrities. In the same way, eyeglasses with sun tints (employed to shield an owner's eyes from too much UV rays from the sun) are made to appear fashionable apart from their major function.
If you are the type whose occupation or interest requires you to be glued on the computer screen for so many hours in a day, you would be advised to acquire computer-tinted prescription glasses which are capable of filtering ultraviolet rays emitted by the computer glare. Additionally, this type carries with it an anti-reflective coating and a colored tint that improves screen contrast. Computer tints prevent blurring of the eyes, eyestrain and headaches associated with prolonged use of computers.