A contact lens fine-tunes the light that enters your eyes by redirecting it to a single focal point on your retina. This corrects refractive errors such as myopia and hypermetropia.
A contact lens fine-tunes the light that enters your eyes by redirecting it to a single focal point on your retina. This corrects refractive errors such as myopia and hypermetropia.
A specialized contact lens can also correct for astigmatism, which is a variation on these refractive errors. A contact lens with a multifocal design includes several focus zones that have different refractive powers.
Soft Contact Lenses
Soft contact lenses are made of flexible, thin plastic and conform to the shape of your cornea. They can improve your vision if you have myopia (nearsightedness), hyperopia (farsightedness), astigmatism, or presbyopia (blurry near and distant vision as you get older).
Modern soft lens materials have a high oxygen permeability and a relatively low coefficient of friction against the cornea, making them very comfortable to wear. They are also available with cosmetic features and colors.
Soft lenses are inserted by holding one on the pad of your index finger and sliding it across the sclera. They can also be positioned directly on the eye by pinching the edge between the thumb and index finger. Some studies suggest that customized, aberration-controlled soft lens modalities may offer a useful form of visual correction for forme fruste and earlier forms of keratoconus (Jinabhai et al., 2014). These modalities should be evaluated in individual cases as their clinical utility has not yet been fully established.
Toric Contact Lenses
Toric contact lenses are designed to correct astigmatism. Astigmatism is caused by an irregular curvature of the cornea or lens, so when light enters your eye it does not bend properly to focus at a single point on the retina and instead scatters around the eye. This causes blurry vision. Toric lenses are designed with different powers in various meridians of the lens to correct this. They are also often weighted or ballasted so they remain in place on the eye and do not rotate during wear.
Your eye care provider will do a comprehensive eye exam and lens fitting to determine if you are a candidate for contact lenses. They will explain the benefits of toric lenses, show you how to put in and remove your lenses, and outline a lens care routine. In some cases, you may need to try several brands of soft toric lenses before finding the ones that work best for you.
Multifocal Contact Lenses
A popular choice for those with multiple refractive errors (myopia, astigmatism, and presbyopia), multifocal contact lenses integrate different prescription strengths into one lens. This helps provide a seamless transition between various viewing distances, reducing eye strain and eliminating the need to continually pause or shift your focus between near and far objects.
These contact lenses are available in both soft and rigid gas permeable (RGP) materials, with many designed to be worn on a daily, 1-2 weekly, or monthly disposable basis. This makes them convenient to use, as you simply throw out the old lenses at a specified interval and replace them with fresh, new ones.
Rigid multifocal lenses feature a segmented design similar to bifocal or trifocal eyeglasses, with the center of the lens containing the power needed for near vision, while the outer portion of the lens is optimized for distance. They also often include a boost of power in the non-dominant eye to optimize near and intermediate distances so that binocular vision is preserved.
Extended-Wear Contact Lenses
The goal of extended wear contact lenses is to provide you with a hassle-free way of getting clear vision without daily maintenance. These lenses can be worn overnight for one to six nights or up to 30 days. These contacts are typically made from silicone hydrogel that allows plenty of nourishing oxygen to pass through to the cornea. The length of time you can wear these contacts will depend on the lens type and your eye care professional’s evaluation of your tolerance for overnight wear.
You don’t have to worry about removing and cleaning your lenses daily, which can help minimize the risk of infections and complications caused by buildup (viruses, bacteria, microorganisms, allergens, lipids, proteins and dust). If you decide to get these contact lenses, make sure you follow your doctor’s recommendations for replacement and lens care, and talk to us if your eyes are itchy or red. These lenses are great for people with demanding professions and lifestyles, like healthcare workers who work long shifts.