Contact lenses make it easier for people with poor vision to work and carry out daily tasks. About 45 million people in the U.S. use them to correct their vision. 

Soft contact lenses are the same size as your corneas and lie on them. Scleral contact lenses are hard and larger than your cornea. They rest on the sclera, the whites of your eyes. Being gas permeable, they allow oxygen to reach your cornea and are better for eye health. They give better vision and can be used for longer periods. They're valuable if you can't wear regular contact lenses due to an irregular corneal shape or a disease. 

The two common types of contact lenses are hard and soft. Hard lenses are often gas permeable, letting oxygen reach your cornea. Scleral contact lenses are larger than soft contact lenses. They're firm, hold their shape, and rest on the sclera around the cornea.

Like other contact lenses, scleral contact lenses correct poor vision caused by refractive errors. They can correct:

Scleral contact lenses are made of gas-permeable material. They allow oxygen to pass through to your cornea. Scleral lenses are valuable if your corneas are abnormally shaped, as in astigmatism and keratoconus. You can also use scleral lenses after LASIK (laser in-situ keratomileusis), a type of surgery to correct refractive errors, or corneal transplants. The space between the scleral lens and the eye is a reservoir that you fill with saline. Scleral lenses are comfortable for people with dry eyes.

Scleral lenses are valuable for people who can't use other types. But they have a few disadvantages:

Soft contact lenses rest on the cornea. They're soft, and most people find them comfortable to wear. But these contact lenses can be uncomfortable for people with dry eye disease, Stevens-Johnson syndrome, Sjogren's syndrome, keratoconus (abnormally shaped cornea), and graft-versus-host disease. People who have had corneal surgery may also be unable to use regular contact lenses.

Scleral contact lenses are larger than the cornea. Most are 14 to 24 millimeters in diameter. They vault over the cornea and rest on the sclera, the tough, white part of the eye. The fluid within keeps the eyes moist for longer.

Scleral lenses are not new. Their advantages in terms of oxygen supply to the cornea have been known for decades. They prevent hypoxic damage to the cornea and may also reverse damage that occurred previously.

You should always use specific solutions meant for contact lens storage and care. Never use water or any detergent solution for your contact lenses. Multipurpose contact lens solution can be used for cleaning and disinfecting your scleral contact lenses. These solutions also condition your lenses. You should replace your storage case every three months.

Other lens cleaning solutions contain hydrogen peroxide. These solutions also clean and disinfect your lenses. They also break up and remove trapped debris, protein, and fatty deposits. Hydrogen peroxide can damage your eyes. You must use a neutralizer that makes it safe to put your lenses into your eyes. A neutralizer is always sold as part of hydrogen peroxide lens cleaning kits. Leave your contact lenses in the neutralizer solution for at least six hours.

The process for putting in scleral lenses is different from that for soft lenses. Your scleral lenses have a reservoir to hold fluid and keep your cornea moist. These steps are needed:

Gas permeable contact lenses are made of a material that holds shape but allows oxygen to pass through. Compared to soft lenses, about two to four times more oxygen is available to your corneas. They're smaller than regular contact lenses and cover about three-quarters of the cornea. They're made of a rigid material and hold their shape in use.

These lenses provide crisper, clearer vision than soft contact lenses. They're more durable and easier to handle. But you may need some time to get used to them. Their cleaning and disinfection process is more complex too.

Your eyes are precious, and taking care of your lenses is important for keeping them healthy. Some important measures include:

Caring for your lenses is vital for eye health. Improper care can cause diseases like keratitis and eye infections. If you have red eyes or your eyes are painful, remove your contact lenses immediately and talk to your doctor. Serious eye infections happen with contact lens use and can cause blindness.

American Academy of Ophthalmology: "Contact Lenses for Vision Correction."

Centers for Disease Control and Prevention: "Healthy Contact Lens Wear and Care," "Healthy Contact Lens Wear and Care. Fast Facts," "Protect Your Eyes."

Cornea: "Medical Applications of Scleral Contact Lenses."

Food and Drug Administration: "Focusing on Contact Lens Safety

University of Iowa Health Care: "Scleral lenses: Large gas permeable contact lenses."

Vision Center: "Scleral Contact Lenses for Keratoconus & Irregular Corneas."

Learn about causes, symptoms, and treatments.

Simple annoyance or the sign of a problem?

Warning signs, myths, and facts.

© 2005 - 2022 WebMD LLC. All rights reserved.

WebMD does not provide medical advice, diagnosis or treatment.