Cataracts are estimated to affect more than 24 million Americans over the age of 40, and by the time we reach 80 years old, at least half of us will be suffering from this condition – which is one of the leading causes of blindness in the world. Cataracts occur when age-related changes to the natural lens of the eye cause the proteins contained within it to clump together, causing cloudy patches in our vision. Cataracts can affect one eye or both, but they are progressive and over time, our vision will become increasingly impaired until it becomes impossible to see. There’s no cure for cataracts, although it is possible to slow the condition. However, the only permanent treatment is to undergo cataract surgery.
Intraocular lenses, or IOLs for short, are tiny, artificial lenses that are used to replace the natural lens of the eye in patients who require cataract surgery. By taking away the clouded lens and replacing it with an artificial alternative, patients with cataracts can have their vision restored. Cataract surgery has an extremely high success rate of more than 95% making it an ideal option for patients at any stage of their cataract development.
Depending on which variety you choose, intraocular lenses are typically made from acrylic or silicone. In addition, they have the ability to block harmful UV rays keeping your eyes safe from the effects of UV damage.
The natural lens of the eye is responsible for refracting the light rays that enter the eye, causing them to focus on the retina and enabling the message sent from the eyes to the brain to be interpreted correctly, resulting in clear vision. Patients with cataracts have a lens that becomes white or yellow and cloudy in appearance. Many people with cataracts liken the effect of looking through frosted glass. Over time, this effect will worsen until the natural lens is replaced with an IOL. An IOL works similarly to a natural lens, except because it is man-made it can’t change shape or get cloudy.
IOLs come in a range of different focusing powers, just like prescription lenses for glasses or contact lenses. To ensure that your IOLs work for you, your ophthalmologist will measure the length of your eye and the curve of your cornea. This information will be used to set the focusing power of your IOLs. And since every patient is different, new intraocular lens technology has facilitated the creation of a range of lenses, so that your ophthalmologist can choose the variety that will best suit your needs. Some of the main types of IOL to choose between include:
Monofocal IOLs. These are the most common type used in cataract surgery and have just one focusing power so that they are set specifically to support vision at one distance. Most people have them set to provide clear distance vision, but then if necessary, wear glasses or contacts for activities requiring clear near vision, such as reading or using a computer.
Multifocal IOLs. As their name suggests, these IOLs provide both distance and near focus at the same time. This is possible by a technology called refractive optics or diffractive optics. The lens has a series of rings in a target formation that enables this. Most patients adapt quickly to this technology.
Toric IOLs. Toric IOLs are designed specifically to correct astigmatism – a condition whereby the patient has a refractive error caused by an uneven curve in their cornea. Toric IOLs have special markers on the peripheral parts of the lens that enable the surgeon to visualize the orientation of the astigmatism correction in the lens. This enables the lenses to be properly aligned in order to achieve the best results.
Your ophthalmologist has the advanced product knowledge and experience needed to help you discover which IOLs will best suit your lifestyle and budget. Some of the areas to consider will include:
Is your chosen IOL covered by insurance? Not all IOLs are covered by insurance. While monofocals which are the most popular are generally covered, the more premium IOLs that can also reduce your need for glasses or contact lenses may not be included in your policy. Therefore, if you are relying on insurance to cover the cost of your intraocular lenses, you may be limited as to which style you can choose. Check your insurance information carefully and speak to your ophthalmologist to find out more.
Do you spend a lot of time in front of a screen? If you spend a great deal of time working on a computer or looking at digital devices, it may be more advisable for you to have your IOL focusing distance set to near rather than far. Alternatively, you may wish to opt for a premium IOL that can give you clear vision at all distances, particularly if you would prefer to avoid wearing corrective glasses or contact lenses.
Do you need to drive at night? If you regularly need to drive at night, you need to have IOLs that support this function. Multifocal intraocular lenses can cause the patient to see haloes or rings around certain lights at night. While most patients are not bothered and accept this it may not be advisable for some.
Do you have any eye conditions? Multifocal IOLs aren’t recommended for patients with vision loss resulting from glaucoma, macular degeneration, corneal scarring and irregularities, and other eye diseases since they let less light into the eye, compromising their vision further.
If you are considering cataract surgery and would like more information about intraocular lenses, don’t hesitate to speak to our expert team.