This study is important to understanding the origin of adverse responses some people have with wearing soft contact lenses and to seeking better lens designs to alleviate them. However, there is always a compromise between increased lens motion and comfort. For this reason, more study is needed to find the range of motion people can tolerate and to design new lenses that can improve the flushing of eye contaminants, he added. Of the nearly 25 million Americans who wear contact lenses, approximately 80 percent wear soft lenses, according to the American Optometric Association. That percentage includes daily wear, extended wear and disposable contacts.
Most disposable contacts use the same materials as daily wear soft contact lenses.
As a result, they also are vulnerable to irritant problems. Newly introduced silicone hydrogel soft contact lenses provide improved oxygen transfer through the lens to the eye but do not eliminate all adverse responses in extended wear, Radke said. Their greater movement and smaller size, however, mean hard contact lenses tend to be more uncomfortable and less popular.