subject: Types Of Contact Lenses [print this page] Contact lenses are lenses that are inserted into the eye to correct poor vision as an alternative for eye glasses. For those that do not wish to wear glasses on a regular basis, contact lenses come in a soft form and a hard form, which is referred to as a rigid gas permeable. The purchase of contact lenses can only be done with a prescription from a licensed optometrist.
Rigid Gas Permeable Contact Lenses
Rigid contact lenses are significantly more difficult to wear than soft lenses. It takes wearers much longer to get used to wearing a hard lens than it does a soft lens. However, they are considerably better for vision correction as they have less buildup and provide sharper vision. Because they are longer lasting than soft lenses they are less expensive than soft lenses when looking at the long term; part of the reason for this is because hard contacts are easier to handle and tear less often than soft lenses tend to do. Hard lenses are not typically approved as extended wear lenses because they do not allow oxygen through the lens that allows the cornea to breathe.
Soft Lenses
Oxygen can pass through the soft plastic material used to create soft contact lenses, which is the reason they are so much more comfortable to wear than hard lenses. Because soft lenses are preferred over hard lenses by most contact wearers, the majority of lenses come in a soft form. Extended wear contact lenses are an example of lenses that are more common in the soft form. The purpose of the extended wear contact is for people that want to continuously wear their contacts without removal. Extended wear lenses can be worn for up to six nights or 30 consecutive days.
Disposable Lenses
Another form of contact lens that is found more commonly in a soft form is the disposable lens. By definition, disposable lenses are lenses that are replaced on a daily basis; meaning the wearer inserts the lenses first thing in the morning and throws the lenses away after taking them out later that evening. However, more disposable contact lenses are made for more prolonged wear. These disposable lenses are not disposed of at the end of the day - they are worn for a period of time, typically every day for the time between one week and one month, and then disposed of.
