Safety of contact lenses, like lawn mowers and automobiles, depends far more on human behavior than on the technology. It is a fact that few technologies start out with the intention of hurting people directly or through the environment, and most emerging threats to people are eventually recognized. It is also a fact that no situation in this world exists that cannot be made much worse by human ignorance, laziness, and stupidity.
So, how can people make good contact lenses unsafe?
The most common hazard is careless cleaning habits. The eyes and tears produce various proteins which can build up on contact lenses. Proper cleaning procedures will remove that build up. Getting lazy, skipping a scheduled cleaning, using old solutions or previously used stock, these can all result in film build up. At a minimum, this can result in blurred vision and/or blurred vision. It can also cause infections and mechanical damage so severe as to prevent further use of contacts, or even cause blindness.
The second most common risk factor is external contaminants and dirt. Don’t swim or go into hot tub while wearing contact lenses unless they are covered by leak proof swimming goggles. Don’t wear contacts in the presence of fumes from solvents, acids, cleaning solutions, et cetera. Be alert to dust, pollen, other allergens. Any of those irritants can be trapped under or inside the contacts. And never be so foolish as to moisten lenses in the mouth instead of in a lens case with fresh solution, or with approved eye drops.
The third most common hazard is wear time. This is an issue which is aggravated by claims from some contact lens makers. Stated simply, don’t wear contacts frequently around the clock, even if they are rated for 30 days or 3 months. In the short term, long wear lenses are probably safe. However, in the long term, insufficient reach of oxygen from the air to the eye surface (cornea) causes the eye to increase blood flow through a proliferation of new blood vessels, which can eventually block vision, like cataracts. The progress of this condition, called “neovascularization”, can be slow so not recognized until too late. Unless contacts have to be installed by a care giver, the wearer should seldom omit rest times with lenses out. Some ophthalmologists recommend at least twelve hours off every week with long-wear lenses.
And don’t overlook safety precautions. Just as spectacle users should have break resistant lenses or safety goggles, contact wearers should wear safety goggles when at risk. Rare stories tell of a hard contact lens stopping penetration by pieces of metal or glass that got through the eyelid, but modern contacts cover only a small portion of the eye.
The natural eye has evolved over eons to be largely self protecting. But don’t ignore common sense care to reduce the probability of injury.
For more articles about safe and enjoyable use of contact lenses and spectacles, see us.