Contact Lenses
Introduction
New developments in contact lens technology allow many more people to experience the benefits that contact lenses can provide.
Russell & Jones Optometrists provides an excellent contact lens alternative for nearly any prescription. Depending on your requirements, we can fit extended wear lenses (up to 30 nights continuous wear), daily disposables, toric lenses to correct astigmatism and multifocal lenses.
Michael has extensive experience in fitting rigid lenses for difficult prescriptions in cases such as kerataconus and post-corneal graft, as well as orthokeratology (overnight myopia control), and is happy to discuss the alternatives with you during your consultation.
General Contact Lens Information
Contact lenses are small pieces of complex plastic that are placed directly over the cornea and can correct myopia, hyperopia, presbyopia and astigmatism.
Contact lens wear schedules include daily wear, designed to be work during the day and taken out at night, or extended wear, which can be worn overnight.
Depending on their replacement schedule and lens type, contact lenses fall into several categories:
- Conventional soft (Hydrophilic) lenses
- Gas permeable (rigid contact lenses
- Disposable lenses
- Extended wear lenses
- Combination lenses
- Ortho-K lenses
- Special purpose lenses
Conventional Soft Contact Lenses
Soft contact lenses are made specifically to the patient's prescription. Not all patients can wear disposable lenses and there may be other reasons why a conventional soft contact lens is prescribed. The life of a conventional soft lens is typically one-to-three years.
Gas Permeable (Rigid) Contact Lenses
Gas permeable (GP) contact lenses allow more oxygen to transmit into the eye than soft contact lenses. While GP lenses are not as flexible as soft lenses, they contain silicone, which gives them a greater flexibility and significantly more oxygen permeability than traditional hard lenses.
GP lenses take a little longer to adapt to, but provider sharper vision correction and are more appropriate than soft lenses for people with conditions such as astigmatism. They are also necessary for specific conditions such as the correction of keratoconus or other irregularities of the cornea.
Disposable Soft Contact Lenses
Disposable contact lenses are designed to be worn during the day and replaced on a regular basis, whether daily, weekly or monthly. The replacement schedule of disposable contact lenses depends upon the prescription and the type of material from which the lens is made.
Frequent replacement of contact lenses provides greater comfort and reduces the risk of infection from the build-up of protein, calcium and lipids that occur naturally in the eye.
Extended Wear (or Leave-In) Contact Lenses
Extended wear contact lenses are usually soft contact lenses which allow more oxygen to reach your cornea. Depending on the type of lens, extended wear contact lenses can be worn without removal for seven-to-30 days.
Extended wear contact lenses are not reusable, thereby reducing the risk of infection that occurs with lens cleaning and reuse.
Combination Contact Lenses
Combination contact lenses consist of a rigid centre lens with a surrounding soft skin. They are normally used in specialist practices mainly for medical purposes such as distorted or damaged corneas.
Ortho-K Contact Lenses
Orthokeratology lenses are used to correct the lower levels of myopia by wearing a rigid gas permeable lens overnight. Each lens is designed specifically for an individual cornea and utilises the fluid layer trapped between the lens and the eye to remodel the corneal shape.
The lens is removed on waking and gives clear vision over that day, sometimes longer. There is also early evidence that this procedure may slow down the progression of myopia in teenagers. Not all contact lens practitioners do ortho-k work and you should discuss the pros and cons of this with your own practitioner.
For more information on ortho-k lenses, see our ortho-k page.
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