Obtaining a correct prescription from your doctor is the first important step in seeing well, but not the last. Selecting the right lenses for your glasses is a critical and yet poorly understood factor. This is especially true for seniors, patients who spend lots of time on computers, sports enthusiasts and those with certain eye diseases.
Seniors aged 65 need about six times the amount of light to see as well as a twenty year old due to various changes in the cornea, lens and retina. A normal untreated plastic lens loses about 8% of light due to reflections and a high-index lens loses about 12%. The only way to combat this loss of light is with anti-reflective (AR) coats, which increase transmission to about 99%. The best AR coats have built-in warranted scratch coats, which provide a type of insurance on the lenses against scratching. Seniors are also more sensitive to glare, which may be annoying or incapacitating. This problem is dealt with by utilizing photochromic lenses that change color or with separate polarized sunglasses. Even the color of the tint will affect the vision in different environments.
Computer users face many special visual demands. Those with moderate computer use will often find one of the better progressive lenses works adequately. Less expensive progressives are not recommended because the clear zones tend to be too narrow for comfort. Those who put in long hours on the computer often find greatly improved visual comfort with a pair of glasses designed exclusively for computer use. This usually results in the best vision and comfort.
Sports enthusiasts also face unique sets of visual demands. Most tend to do well with the AR coats because of the increased light transmission. When glare is an issue, such as skiing, on the water or biking on roadways, glare-blocking polarized lenses are a must. The differing demands of golf, tennis, shooting sports and water sports all have specific colored tints that are used to enhance performance.
Finally, different eye diseases are made worse by certain wavelengths of light, requiring tints or UV protection. Cataracts and macular degeneration are of the most common such conditions.
As you see above, the correct prescription focuses your vision well, but other lens considerations can make a significant difference. AR coats, polarizing lenses and selected tints can make the difference between “OK” and GREAT!