Choosing IOL Cataract Surgery

With age, the lens in the eye gradually deteriorates and becomes cloudy, eventually affecting vision. This degradation of the crystalline lens is called a cataract. At this point, replacing your glasses will not improve vision. The most effective method is through cataract removal and intraocular lens (IOL) implantation. With current advanced technology, the success rate of cataract surgery is as high as 99%.

There are various cataract surgery options involving different methods. These advanced techniques have enabled unprecedented progress in eye surgeries, bringing vision back into patients’ lives.

Currently 98% of cataract surgeries in North America are performed with phacoemulsification, an ultrasonic method. After liquefaction, the lens tissue is aspirated out. A 2-3 mm incision allows a new artificial intraocular lens implantation. The entire operation takes 5-10 minutes under local anaesthetic and is performed as a day-surgery. Postoperative recovery time can be from a few days to two weeks. The outcome after the procedure is usually excellent.

An intraocular lens implant helps restore patient vision without the need for thick glasses. All hospitals in Ontario provide a choice of intraocular lenses. However, OHIP only covers a basic lens; specialty lenses can be used if paid for by the patient.

  1. Basic Lens: This lens allows for only a single focal length and most patients choose to have the lens set for distance vision. They will still need glasses for reading after surgery. OHIP supplies this lens.
  2. Blue Block Lens (Blue filter + HOA): This lens has a single focal length. Most patients choose to have it set for distance vision. They will still need glasses for reading after surgery. This type of lens reduces ultraviolet and blue light stimulation of the retina and may offer protection of the central macula. This is important as central macular degeneration is common as one ages. Also, this lens reduces “Higher Order Aberration” (HOA), improving vision, in particular night vision.
  3. Dual Focal Length Lens (Multifocal IOL): This lens is the most advanced intraocular lens available. Used over the past 10 years in the United States and Europe, patient satisfaction has been high. 90% of patients no longer need to wear glasses, while 10% of patients may sometimes need low-power glasses. The lens allows the patients to see both near and distant objects.
  4. Astigmatism Lens (Toric IOL): If the eye is spherical, it can focus on the retina well. But 20-25% of the population have an egg-shaped cornea which has two focal distances, resulting in two images on the retina. Focusing is imprecise and the image is unclear. Astigmatic patients who choose this lens can correct astigmatism (+1.50 D to +6.00 D). Often after surgery they no longer need glasses for distance but still require reading glasses.
  5. Multifocal Toric intraocular lenses have been available in Canada since February 2011. This type of lens combines the properties of both Multifocal and Toric IOLs. It can be used to eliminate astigmatism, and allows the patient to see both near and far without glasses. There are some limitations and you need to discuss this option with your doctor or eye professional to see whether you are a suitable candidate.


  1. Intraocular Lens – Wikipedia

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