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Types of Contact Lenses

There are generally two types of contact lenses: Rigid gas permeable lenses and Soft contact lenses.

Rigid gas permeable lenses, also known as hard contact lenses, are made of a firm material that is able to maintain its shape. These lenses are typically more durable than soft lenses and can last several years with proper care. Hard lenses can provide good oxygen permeability, although modern soft lenses also vary greatly in how much oxygen they let through.

Soft contact lenses, on the other hand, are more flexible and better adapt to the shape of the eye. They are made of a soft, flexible material that is able to absorb fluid and retain moisture. Some are daily disposables that you throw away after one use, while others are reusable and designed to be replaced after a week, two weeks or a month.

There are also other types of contact lenses that have been developed to meet specific needs, such as toric lenses for correcting astigmatism, multifocal lenses for addressing presbyopia, and colored lenses for changing eye color.

Advantages and Disadvantages of Hard Contact Lenses

One of the main advantages of hard lenses is that they have a longer lifespan than soft lenses and can typically last several years. They are also more resistant to protein and other substance deposits that can impair vision.

Hard lenses can also provide particularly precise vision correction for some people with astigmatism, although suitable soft toric lenses are another option. Although they are initially more expensive than soft contact lenses, they prove to be cost-effective in the long run because they need to be replaced less frequently.

On the other hand, hard lenses may be uncomfortable for some people to wear and require a longer period of adjustment. As they are less flexible than soft lenses, they may be more noticeable when worn and cause more irritation to the eye. With hard lenses, there is also a higher risk of them falling out of the eye compared to soft lenses.

Advantages and Disadvantages of Soft Contact Lenses

One of the main advantages of soft contact lenses over hard lenses is that they are more comfortable to wear and can better adapt to the shape of the eye. They can also be worn during sports or physical activities, as they are less likely to fall out of the eye than hard lenses.

Soft lenses contain water, but that does not necessarily mean they prevent dry eyes. Comfort and dryness depend on the lens material, the tear film and how the lenses are worn.

However, there are also some disadvantages to using soft contact lenses. Reusable soft lenses need to be cleaned, stored and replaced properly. Deposits and microorganisms can build up on the lens surface or in the storage case, which can increase the risk of eye infections. Daily disposable lenses are different. Since you use a fresh pair every day, there is no need to clean or store them overnight, and the storage case cannot become contaminated. That removes some of the risks associated with reusable lenses, but daily disposables are not completely risk-free either.

Soft monthly lenses have a limited lifespan and need to be replaced according to the manufacturer's schedule, usually about one month after opening. Wearing them longer than recommended can allow deposits to accumulate and increase the risk of irritation and infection. No matter which soft lenses you use, avoid sleeping in them unless specifically prescribed, keep them away from water and handle them with clean, dry hands.

Personal Experience with Complications

I learned this lesson the hard way: I often wore my monthly contact lenses beyond the recommended one-month duration, as they still looked good and I thought they were still working well. However, one month ago, I woke up with severe eye pain and my vision was blurry. My wife took me to the hospital, where the diagnosis was massive endothelial deposits. I was given special eye drops and sent home.

The next day, the pain became unbearable, and I was brought to the hospital again, this time with my father by my side. Fortunately, the senior doctor was present and took ample time to examine me. He found that the corneal epithelium was strongly stippled, very loose and movable. The drops I had received earlier were also wrong and had worsened the situation.

By using the right eye drops and a vitamin A eye ointment, along with a week of bed rest, I narrowly avoided a corneal injury.

The senior doctor explained the problem with repeatedly wearing and storing soft monthly lenses. He compared them to a sponge that collects bacteria over time. That's a simplified explanation, but the underlying risk is real. Deposits can accumulate, and microorganisms can stick to lenses or contaminate the storage case. The longer reusable lenses are worn beyond their intended schedule, the harder it can be to keep them clean. For the future, he recommended either glasses or hard contact lenses. Daily disposable soft lenses deserve a separate mention here, though, because you throw them away after one use rather than cleaning and storing them again. My experience was with monthly lenses, not daily disposables.

Closing Words

Contact lenses offer many conveniences, but as I painfully experienced, ignoring the recommended replacement schedule can have serious consequences. That's why I plan to try hard contact lenses in the future and occasionally switch to my glasses. Daily disposables are also worth considering for people who want to avoid the cleaning and storage routine of monthly lenses. Whatever type you use, don't assume that everything is fine just because the lenses still look good.