There are many different types of contact lenses and some will work better on your eyes or with vision correction. Talk to your eye doctor about which lens is best for you. If you do not already wear contacts, ask them to help find the right lens for you before starting this type of extended wear.
Soft Contact Lenses
Soft contact lenses are worn directly on the eye, just like hard contacts. They are usually prescribed to people with keratoconus, dry eyes, allergic reactions to eye drops, or allergies.
The only difference is that soft contacts are made of extremely thin and flexible contact lens material that closely conforms to the shape of your eye surface.
Soft contact lenses use a silicone hydrogel material called “extended wear” which means they can last up to 1 month before they need replacement or reinsertion while hard contacts need to be replaced every day.
After you put in a new soft lens it will immediately start adjusting and conforming to your eyes’ unique shape and other features such as lid thickness (the amount of tissue separating your eyeball from the air) for better comfort since there’s more flexibility in this design than with rigid designs.
Soft contacts are more comfortable for day-long wear and they protect the surface of your eye from scratches.
They are effective at maintaining moisture in the eye with an extended time of wear but increase the risk for infection. There is also no possibility of scratching delicate corneal tissue as can occur with hard contacts.
Rigid Gas Permeable (RGP) Contact Lens
Rigid gas permeable contact lenses have a ‘rigid’ material that is very resistant to swelling. This means that your natural tears are not enough to clean the surface of your eye and should be treated with artificial tears or saline solution more often.
Ultimately, you will most likely find them irritating because they take longer to get used to than soft lenses. They also tend to irritate people’s eyes (both due to their design and their potential for leaks).
Rigid Gas Permeable Contact Lenses are rigid in nature but were originally made of highly swollen hydrogel material. Rigid Gas Permeable lenses have the capability to change their shape yet still maintain a small thickness.
The newer types can be made from more flexible materials which expand when it comes into contact with the fluid and shrinks back to its original size once the fluid is removed.
This new type also has no edge on its surface, having instead a shape called “acquired curvature”.
Extended Wear Contact Lenses
Extended Wear Contact Lenses are not intended as a permanent solution for vision correction but rather as a 24-hour (or longer) option for those with low-risk factors such as healthy eyes or no history of dryness, allergies, or infection around the eyelids.
They are made of flexible plastics that allow oxygen to pass to the cornea while allowing light through.
A tighter contact lens means less air that needs to be exchanged; people who have astigmatism may need to go with stronger lenses because it is harder for the inner tissue of the eye to get the oxygen it needs.
Once you wear a contact, however, your eyes will adjust and oftentimes you can change up your prescription.
For example, if someone wears tight contacts now but wants to wear soft in the future they will most likely be able to.
Extended Wear Disposable Contact Lenses
A disposable contact lens is a soft lens that you wear for an extended period of time and then discard because it can’t be cleaned. The risk of eye infection is reduced if you follow the instructions on the prescription slip.
One other positive characteristic of this type of contact lens is that they require little to no cleaning. Also, these particular types of extended wear lenses come in a variety of tints and bifocals.
Planned Replacement Contact Lenses
These are daily-wear lenses that are replaced on a planned schedule. The most common is every bi-weekly, monthly or quarterly.
Planned replacement contact lenses are a type of contact lens recommended for use by people with an allergy to hydrogen peroxide.
These types of lenses work differently than daily wear and disposable lenses as they are not made of plastic that is saturated in hydrogen peroxide, the technological innovation that makes them safe for most people who have allergies.
Instead, these contacts are made with silicone hydrogel material (Hydrofilcon A). The silicone does not react adversely with antibodies from your tears while the hydrofilcon A protects your eyes against drying out or infection from dirt or bacteria.
They also help protect against eye fatigue and strain since their thin pores allow gas to escape. This allows enough oxygen to permeate continuously without forming “bubbles
