Soft Contact Lenses
Soft lenses have been around in the United States since the early 1970s. They were originally used much like hard lenses in that you would replace them annually or longer. These lenses were great in that they were softer feeling in the eye. The type of soft lenses originally made, called hydrogel lenses, did not allow much oxygen to pass through the lens to your eye. Damage to the eye can occur if the cornea does not receive enough oxygen. This led to the production of better materials that allow oxygen to pass through the lens more freely. Today we have silicone hydrogel lenses, which allow for extended wear (sleeping in lenses). These soft lenses allow the most amount of oxygen to pass through the lens.
There are over one hundred different types of soft contact lenses available for your doctor to choose from when fitting you in contact lenses. The measurements taken of your eye will help your doctor determine which lenses would work best. The doctor may also ask you some additional questions to help narrow the choice even further. Some lenses are better for those with dry eyes. Some are better for those with allergies. Others are good for people who wish to sleep in their contact lenses.
What types of prescriptions can use these lenses?
Near-sighted, far-sighted, and those with astigmatism can use soft contact lenses. Those who need bifocals can try multifocal soft contact lenses. The amount or direction of astigmatism can affect which soft contact lens is chosen for you.
How does it work?
The soft lens contains power to help correct your refractive error. The calculations for contacts and glasses are different because the contact lenses will sit directly on your eye. For those with astigmatism, the lens has one power in the horizontal direction and another in the vertical direction. It is very important for your eye doctor to see these lenses on your eyes to determine if the lens is moving too much, which can cause the power in the lens not to line up correctly with your eye. This can cause your vision to blur.
How are they used?
Soft contact lenses are used for people who do not wish to have rigid lenses. They are great for people involved in sports. They are also good for those with allergies because they can be thrown away after they are used. They also come in some types that have color painted on the lens, which can appear to change the color of the eyes for those who wear them.
How do they handle?
Because they are soft, they can fold inside out when you try to handle the lens. This can be problematic for new wearers. Many new soft contact lenses handle better because the silicone in the lens allows it to hold its shape better. Not everyone can use lenses that contain silicone.
Many people feel that they are harder to learn to use than RGP lenses because they are larger in size and fold easily. But with the proper instruction, almost every person who wants to learn can use soft contact lenses eventually. Although it doesn’t happen often, they can tear while on your eye, which potentially exposes your eye to bacteria and causes irritation. Because soft contact lenses are replaced according to a schedule, they cost a set amount per year. That means you will buy a new supply each year that you want to wear soft contact lenses.
More frequent replacement keeps the lenses fresh on your eyes, which reduces dry eyes and allergies. Soft contact lenses tend to have less initial lens awareness and better comfort. If something happens to your lens, it can easily be replaced because you will have a supply of lenses available.