Most contact lenses can be quite demanding on the tear film. Soft lenses can lose water content over time, when this happens moisture is drawn from the ocular surface. This is why people with dry eyes find that their wearing time is less than expected. A good tear volume is needed to keep the lens hydrated which makes lens wear more comfortable for longer. Some lenses have differing water contents so will have differing dry effects. Newer lens materials have been shown to have better moisture retaining properties.
Rigid gas permeable lenses work by forming a tear layer between the lens and the cornea. This tear layer is needed for the correct fitting of the lenses and to provide optimal visual correction. If insufficient, the lens will rest too much onto the cornea and can cause too much friction on the surface. At the same time, poor vision correction occurs without a decent tear layer. It is therefore even more important that there is an adequate amount of tears for rigid gas permeable lens wear.
Specialist lenses are recommended when conventional contact lenses are not tolerated.
Being part of Burnett Hodd & Tam Optometry – a contact lens specialist practice, our specialists can refit your contact lenses to optimise your comfort in visual correction.
Specialist scleral lenses are particularly useful in moderate to severe dry eye where discomfort is caused by drying and damage to the corneal surface. A scleral lens provides protection of the cornea by the way it is fitted. Most other types of lenses rest onto the cornea which causes friction to the surface and can irritate the eye, especially in dry eye. Scleral lenses are fitted so that it vaults over the cornea and rests on the sclera. The lens is filled with saline so that the cornea is constantly bathed during wear.
Scleral lenses are also useful for people who have moderate to high prescriptions and rely on contact lenses for vision correction.
Scleral lens fitting is provided in our Burnett Hodd & Tam Optometry clinic.
For some patients, dry eye symptoms are mainly present during contact lens wear. OrthoK lenses are becoming increasingly popular in the management of dry eyes. These are lenses that are worn during the night to reshape the corneal surface. The reshaping provides correction of your prescription to give clear vision during the day. This is a reversal effect so there is no concern of a long-term change.
This option enables you to be glasses and contact lens free during the day. It is ideal for people who are short-sighted of up to about -5.00D with low astigmatism.
Read more about our OrthoK fitting