Such messages may sound costly to businesspeople, but FitzGerald and others argue that the investment is a sound one in potential customers. They don't want dead space. But they need an effective use of space. A common eye disease among older people is cataracts, in which a cloudy layer develops in the lens or eye capsule. About half of all individuals in their 80s have some degree of cataracts, says Bresnick.
Untreated cataracts can cause blindness, but cataract surgery is common and has a high success rate.
Individuals with cataracts suffer from reduced visual acuity, which can include blurry vision or vision that gets worse in bright sunlight. Using larger type and bold contrasting colors increases the odds that people with cataracts will see advertising and other print material. Another condition that afflicts older eyes is age-related macular degeneration, which results in blurred vision and can lead to blindness. About 1.7 million Americans have some visual impairment from this disease, according to the National Eye Institute in Bethesda, Maryland. The disease develops when blood flow to the macula, the central region of the retina, is restricted as the small blood vessels of the eye narrow or harden.