Intraocular lenses for cataract
When you have cataracts, your eye doctor probably has discussed with you about cataract surgery and intraocular lens implantation. Cataract surgery involves removing a cloudy natural lens and replacing it with an artificial lens (IOL). There are various types of intraocular lenses and you should know their differences to pick the right intraocular lens for your eyes.
1. Standard Intraocular Lens (Standard IOL)
When you decide to have standard lens, you can only choose to correct for either distance or near vision. If your distance vision is corrected, you will need glasses for reading or vice versa. Unlike the natural lens, this plastic lens can not change its shape to focus your eyes at varied distance. Depending on your daily activities, you should decide whether you want your distance or near vision corrected. Standard intraocular lens is covered by medicare.
2. Toric Intraocular Lens (Toric IOL)
If you have cataract and astigmatism, toric lens may be your best choice. Astigmatism can also be corrected with a procedure called limbal relaxaing incision (LRI) during cataract surgery with a standard IOL, but Toric IOL is more precise to correct astigmatism.
3. Multifocal Intraocular Lens (Multifocal IOL)
Multifocal cataract lens can correct for both distance and near vision. If you have presbyopia, you will have an added advantage that you may not need reading glasses after cataract surgery.
4. Monofocal Intraocular Lens (Monofocal IOL)
Monofocal cataract lens is an alternative to multifocal or accomodative intraocular lens to correct presbyopia in the eye. For this technique, you should have cataract surgery in both eyes in which one eye gets intraocular lens for distance or mid-distance and another eye gets for near.
5. Accomodative Intraocular Lens (Accomodative IOL)
Accommodative cataract lenses are designed to restore accommodation after cataract surgery. Our natural lens in the eye is flexible and able to change its shape to focus at near, intermediate and distance. When the cloudy natural lens is removed and a non-accommodative intraocular lens is implanted, it can not focus at varied distance. But accommodative intraocular lenses change its position with the contraction of ciliary muscles, and provides unaided clear vision.
If you are considering cataract surgery, consult with your ophthalmologist to discuss which intraocular lens is right for you.
How is the strength of an intraocular lens determined?
In the past, no intraocular lens were implanted during cataract surgery, and as a result, you would have to wear thick glasses to see clear at distance and near. With the advancement in cataract surgery, it has been possible today to implant an artificial lens in the eye to replace the natural cloudy lens. Our natural lens has the focusing power of 15 to 20 diopter, and determining an individual’s lens power requires a measurement called A-scan/IOL Biometry. This test takes measurements of the eye including axial length, corneal curvature, anterior chamber depth, corneal thickness etc. and calculates using various formulas to predict the strength of an artificial lens that is to be implanted during cataract surgery.
Do I need glasses after cataract surgery?
Although your eye surgeon try to get best vision without requiring glasses after surgery, it is not always possible. You might still need glasses after cataract surgery. Many other factors determine the outcomes of cataract surgery.