Intraocular Lens Options For Cataract Surgery

The clouded lens is replaced with a standard IOL that is made to correct vision in that eye for either near or distance. The new IOL does not correct both distances so you will need contacts or glasses to see at the distance that the new IOL does not correct.

Standard IOLs are entirely covered by Medicare, which is a great benefit to patients. For premium lens, such as multifocal to correct astigmatism, or are made of premium materials, there may be an out of pocket charge over Medicare or other insurance. 

For correcting astigmatism, there is a toric IOL designed for the same purpose as a toric contact lens. These also may cost extra because they are considered premium lenses and are usually offered as an option. 

Toric lenses can generally correct an astigmatism considered moderate, such as from 1.00 to 3.00 D. Cataract surgeons may also use an AK–astigmatic keratotomy–or an LRI–limbal relaxing incision—small incisions made on the cornea in strategic places.

With a toric IOL placement is critical since the lens orientation must be perfect. If the lens should rotate, another surgery may be required to replace the lens or correct its movement.

A normal IOL curvature is uniform. The curve of an aspheric IOL is more flat near the edge. The flatter edge helps to reduce aberrations, especially spherical aberrations.

Some evidence exists that contrast sensitivity is improved with an aspheric IOL more than with a standard IOL. Even though IOLs provide clearer vision and greater contrast than a clouded one, the ability to see contrast ultimately depends on a healthy retina and even more so, on the health of the ganglion cells.

Bausch & Lomb, Alcon and other companies currently offer aspheric IOLs.

The monovision IOL is not really a specific kind of lens in itself. It actually is having an IOL in one eye designed for near vision and the IOL in the other eye made for distance vision. This is exactly the same as having a patient wear monovision contact lenses.

Before having this kind of cataract surgery, it is important to determine if you are comfortable with monovision and can adapt to this plan. Many people who agree to this type of surgery already wear monovision contacts, so they know that they like monovision. Ask your doctor to give you a trial with monovision contacts before having the procedure done if you are unsure of your comfort level. One drawback in having monovision is that binocularity—both eyes working together–and depth perception will be out of balance. A medium distance such as a computer screen will not be entirely clear because each eye is corrected for a different distance and neither one is corrected for an intermediate distance.

A few doctors are attempting to achieve modified   monovision by mixing the IOL types. They may use an IOL for multifocal and distance in one eye and correct the other eye for near and intermediate vision.

The outcome is less than optimal at times with cataract surgery. In this event, a way to correct vision is by adding a second lens inside the eye as a piggyback on the original IOL placed in the eye.

The piggyback procedure is not performed often but is considered better than removing the original IOL and putting another lens inside the capsular bag.

A natural crystalline blue light IOL filters blue light. After surgery, many patients report that everything seems much brighter and that there is also much more of the blue light. An IOL with a blue light filter mimics an eye's natural lens in its clear state. The only drawback with a blue filtering IOL is contrast sensitivity especially in dim light.

In 2005, Medicare changed the rule regarding premium IOLs. This means just the difference in cost is payable, not the entire cost. An IOL upgrade is now more affordable for many patients.