A lens implant is a precisely manufactured artificial lens, available in a range of styles and strengths. Your consultation with Mr Rossiter includes deciding which type of lens best suits your requirements.
Lens technology has come a long way since its conception in the late 1950’s. There are now lenses that can correct very high spectacle prescriptions, including astigmatism and even can provide excellent intermediate and near vision without spectacles.
The human lens plays a vital role in focusing light for the eye and therefore, after removal of cataract (a cloudy lens) an artificial lens implant is required to perform this function.
Because the implant is placed in or near the original position of the removed human (but cloudy) lens, excellent vision can be restored. Artificial lenses are intended to remain permanently in place, require no maintenance or handling, and are neither felt by the patient nor noticed by others.
The first type of lens implant invented, these remain the most commonly implanted lenses today and are still the only type of implant available on the National Health Service. They have equal focusing power in all regions of the lens and can provide high-quality vision at a single focal point (usually at distance). However, monofocal lenses do not correct astigmatism and usually require corrective glasses for all near tasks, such as reading or writing.
Multifocal intraocular lenses have a number of regions with different power within the lens that allows individuals to see at a variety of distances, including distance, intermediate, and near. The technology and therefor the results are improving all the time.
These lenses can occassionally cause more glare and extra images than monofocal or toric lenses, but these symptoms usually ease with time and typically few patients notice them 6 months after surgery.
Toric lenses correct for astigmatism and as such have extra power in one specific region in the lens (similar to spectacles with astigmatism correction in them). Due to the difference in lens power in different areas, the correction of astigmatism with a toric lens requires that the lens be positioned in a very specific configuration.
Both monofocal and multifocal lenses come in toric versions for patients with visually significant astigmatism.