Understanding the Different Types of Contact Lenses
There are two main types of contact lenses: spherical lenses and toric lenses. As glasses lenses are usually shaped differently depending on the kind of correction your eyes need, contact lenses also are shaped differently as well. Most spherical contact lenses are round-shaped, while toric lenses are oblong-shaped. Both types of lenses are used in the same way for treating different eye problems, so here’s a quick overview of how they work.
Both types of contact lenses
have a common mechanism for working. When a light touches the surface of the eye, a molecule of water is created. The contact lenses then form a thin layer over the water. Spherical contact lenses are designed especially to correct astigmatism, myopia, and hyperopia, while toric lenses are specially designed for treating presbyopia.
Although both types of lenses
can be used for treating many eye conditions, they differ in several ways. For example, conventional hard lenses are generally hard plastic lenses that sit on top of the cornea (the transparent dome-shaped window covering the front of your eye). They are rigid, so they won’t bend or slide when you blink. To maintain good vision even if you wear conventional hard lenses, these lenses require special prescriptions from your ophthalmologist. Contacts on the other hand are generally thin plastic films that sit on top of the iris (the colored portion of your eye). This means that contacts can be used by people with any eye condition and without the need for a prescription.
In addition to providing a clear vision,
many people use contact lenses to treat certain eye disorders. For example, many people use rigid gas permeable lenses to treat myopia, which is an eye problem that causes the eyes to experience blurred images. Since rigid gas permeable lenses cannot be bent or compressed like conventional hard lenses, they offer the only way to treat myopia. However, they also limit the amount of stretching that can be done to correct eye alignment problems.
A different type
of corrective lenses are soft contacts. Soft contact lenses allow more flexibility than rigid lenses because they can be placed and removed more easily. Additionally, soft lenses can contain a variety of tiny beads that provide resistance to grinding, abrasion, and other wear and tear processes. Because they have less structure than rigid lenses, soft contacts can be worn longer before requiring replacement. Also, they do not form a hardcover over the eye like rigid lenses do, which allows more oxygen to get to the eye. However, soft contacts can make the eye feel sore for some people, so it is important to follow the instructions provided with the contacts to avoid dryness.
People who have myopia or astigmatism
can benefit from wearing both types of contacts. Contacts that improve astigmatism can improve myopia and vice versa. However, if you suffer from dry eyes, you should wear lenses only when necessary to avoid irritation caused by saliva. It is also important to consult your doctor if you wear contact lenses regularly to ensure that your dosage is correct and that you are not taking too high or too low of a dosage.