These days, modern technology makes it possible for many medical problems to be overcome by using man-made replacements within the body. Your eyes are no different, and in the same way as we can have hip and knee replacements, it is now possible to substitute the lens of the eye with an artificial alternative to improve eyesight.
Intraocular lenses (also known as IOLs for short) are implanted inside the eye to replace the natural lens, usually as part of cataract surgery. This type of surgery is known as refractive lens exchange.
A cataract is a clouding of the eye’s lens over time, which results in impaired vision. This usually happens in people over a certain age (around 60) but can occur in younger people too. The change is not sudden, but after a while patients start to report difficulty with their vision.
The condition was once thought to cause permanent sight loss, but eye surgeons came to realise that they could treat cataracts successfully by removing the cataract and replacing it with an artificial lens.
IOLs have been used to treat cataracts since the early 1980s. Prior to their use, patients who had cataracts removed had to rely on very thick glasses or special contact lenses to replace the natural focusing power of the eye lens.
IOLs are also used (although less commonly) to correct refractive errors known as presbyopia. This condition results from a decreased flexibility of the natural lens which makes focusing on close objects or reading very difficult. Again, in this situation, IOLs are used as a substitute for the natural lens.
Types of IOLs
IOLs have come a long way since their inception and first use in the 1980s. These days there are a number of types of basic and premium IOLs, giving patients a wide range of choice depending on their needs.
One of the most common uses of IOLs is to improve vision over distance, which means patients will still require glasses for focusing on close up tasks. However, there are IOLs for near vision needs too. Some IOLs offer UV protection, while others correct specific conditions such as presbyopia and astigmatism.
- Aspheric IOLs
These are premium IOLs that mimic the shape of the natural lens of the eye. Because they match the shape and optical quality of the natural lens they provide sharper vision, especially in low light conditions.
- Toric IOLs
These are the IOLs that correct astigmatism as well as near and far sightedness. They come with specific markings on the lens, which can be aligned by the surgeon during a cataract procedure to correct the astigmatism or other conditions. Toric IOLs have made correcting visual impairment issues during surgery significantly easier and less likely to result in complications.
- Accommodating IOLs
These premium IOLs come with an aspheric design and flexible supporting legs that secure the lens in the eye. This allows the IOL to move forward slightly when focusing on near objects, providing more flexible vision than traditional mono-focal lenses.
- Multifocal IOLs
With added magnification in different parts of the lens, these IOLs give you an expanded range of vision which lets you see both objects at distance and close up.
Not an IOL as such but rather the technique of fully correcting one eye with an IOL and making the other eye intentionally near sighted. This means that your eyes adjust, with one giving clear vision at distance and the other better at focusing close up.
- Different IOLs in each eye
Sometimes after cataract surgery the best option might be to have a different IOL solution in each eye. For example, if you suffer from astigmatism in one eye, it may be suitable to have an aspheric IOL in one and an accommodating IOL in the other.
How to choose your IOL
Of course, the type of IOL most suitable for you depends very much on your individual circumstances. The only way to know what your best options are is to discuss them with your eye surgeon.
At a consultation, they will be able to assess your needs and present you with the most suitable options. This may involve a straightforward IOL replacement (in the case of cataracts) but could equally involve laser cataract surgery, for example, if multifocals are your best option.
If you’re over the age of 60, cataracts are far more likely to play a part in your decision to opt for lens replacement surgery. However, younger patients who experience problems such as eye injury or genetic eye conditions may also be candidates.
Our Optegra world leading eye surgeons will assess your needs and advise you on the best options for better vision. We’ve helped over a million patients improve their eyesight, with superb consultant care from start to finish.