Although the primary use of eyeglasses is to correct defective vision, you will need to consider other criteria when choosing the correct lenses. Safety and convenience of use are important factors in choosing the right eyeglass lens. While the type of frame you choose mainly decides the cosmetic appearance, the thickness of the lens is also a contributing factor. Choosing the right lens needs comparison of properties that are unique to your particular vision and needs.
1 Check your prescription. Your eyeglass prescription will contain two main figures — the sphere power and the cylinder power. The values of both these powers will decide which eyeglass lens material is best for you. Lens materials vary with the range they can correct vision. Plastic lenses, for example, cannot be used in higher prescription powers. Glass lenses are good but heavy and thick — hence, they can be used only if your eye power is mild. Check your sphere and cylinder power. Speak to a local optician and ask about the prescription range that is available. Compare only those materials, which are recommended for your eye power.
2 Consider your lifestyle. If you are outdoors for longer periods, compare between lens material such as polycarbonate and high-index plastic lenses that provide the greatest protection from the harmful ultraviolet radiation in sunlight. If you are physically active, compare the impact resistance of the lens materials. If a major part of your life consists of driving is at night, compare lens materials for their anti-reflective and anti-glare abilities. Lenses that are coated with anti-reflective materials are safest in such cases. These lenses are also the most comfortable if your work involves staring at a computer screen for long periods.
3 Consider weight of the lens. Glass lenses are the heaviest among lens materials. Polycarbonate and high-index plastic lenses are lighter than high-index glass lenses. If you are looking for lenses for children, comparing the weight is crucial; polycarbonate is the material of choice for kids’ glasses.
4 Check the effect on appearance. You might have high an eye power that causes your eyes to seem more prominent. Perhaps, cosmetic appearance is important to you. In either of these cases, compare between lenses that have anti-reflective coatings — these lenses, appear thinner and give a more natural look.
5 Compare prices. Plastic lenses are the most economical. Glass lenses are also priced low, but they are heavier. Considering the fact that safety and convenience are more important, do not scrimp on prices while selecting the lens material.
Tips & Warnings
The lens materials that are thinnest, lightest and most attractive are also the most expensive ones.
None of the eyeglass lens materials are naturally scratch resistant — not even glass. Lenses can be rendered scratch proof with a special coating.
Eyeglass lenses for people with presbyopia (vision deficiency due to aging) are different from those for people with simple short- and long-sight deficiencies.