The Benefits of Daily Disposables
When soft contact lenses first came on the scene, the ocular community went wild.
People no longer had to put up with the initial discomfort of hard lenses, and a more frequent replacement schedule surely meant better overall health for the eye, right?
In many cases this was so. The first soft lenses were made of a material called HEMA, a plastic-like polymer that made the lenses very soft and comfortable. The downside to this material was that it didn’t allow very much oxygen to the cornea (significantly less than the hard lenses), which bred a different line of health risks to the eye.
As contact lens companies tried to deal with these new issues, they started to create frequent-replacement lenses made from SiHy, or silicone hydrogel. The oxygen transmission problem was solved, but an interesting new phenomenon occurred.
Because these were supposed to be the “healthiest” lenses ever created, many people started to overwear their lenses, which led to inflamed, red, itchy eyes; corneal ulcers; and hypoxia (lack of oxygen) from sleeping in lenses at […]