Intra-Ocular Lens Choices

Every person that undergoes cataract surgery requires an artificial lens to be placed in the eye. This is called an Intra-Ocular Lens (IOL). While the main purpose of cataract surgery is to replace a clouded lens with a clear one, thereby improving visual potential, an additional benefit is the ability to re-focus the eye in the process.

A new generation of IOLs imparts tremendous optical benefits without adding any medical risks to the operation. Today’s IOLs can be folded and inserted through very small incisions and are made of inert material that is never rejected and is intended to last a lifetime, as there are no moving parts.

The ReSTOR IOL can increase range of vision

The ReSTOR intra-ocular lens has become the world’s most popular multi-focal IOL, by combining both refractive optics (focusing by bending light rays) and diffractive optics (focusing by constructive interference).

The Princeton Eye Group is proud to say they were on the forefront on the research that brought this lens to market and are viewed as key opinion leaders in the industry regarding proper use of this technology. All lenses can be considered light gathering devices, and the focus point is that distance at which the majority of light rays are gathered from. The ReSTOR IOL creates two major focal ranges, about 20 feet and 16 inches. This provides excellent distance vision and adequate close focus to create a range of vision referred to as ‘casual near ability.’ This casual near ability makes all the difference in the world in day-to-day living, when you’re on the go. For the most part it gives one the ability to see your cell phone, price tags when shopping, and your food when eating and cooking. It gives you enough near vision that you don’t feel you ‘need reading glasses for every picky little thing,’ which is the complaint of many patients who are over 55 years old or have basic monofocal IOLs set for distance. The ReSTOR lens works better when inserted in both eyes, and in many instances, patients spend their lives basically free from spectacles.

Toric IOLs can neutralize astigmatism

Another tremendous advance is the toric intra-ocular lens, which is designed to correct corneal astigmatism. Astigmatism is a focusing issue whereby two focal points are created by the cornea, which is the clear flexible dome in the front of the eye. This comes about when the cornea is bent more tightly in one direction than the other, like a spoon or the side of a football. That extra bend is called toricity.

The basic concept is that this extra bend can be measured, and applied to the surface of the IOL. When the surgeon inserts the IOL, he/she merely places the extra bend of the IOL perpendicular to that of the cornea, so that the toricities cancel out each other. There is no added medical risk in inserting the lens.

The features of the ReSTOR and Toric IOLs have been combined

Considered the most scientifically advanced IOL, the ReSTOR-Toric IOL combines the features of previous technology and addresses all three components in one’s prescription: the sphere for near-sightedness or far-sightedness, the astigmatism or toricity, and the near power of presbyopia. The doctors at the Princeton Eye Group were involved in the clinical studies and presentation to the FDA to garner approval of this special IOL.


Intra-ocular lenses do not match nature. Owing to the fact that the IOL is smaller than a natural lens, the edge of all IOLs can cause glare. The diffractive aspects of a ReSTOR IOL can cause rings around light sources such as headlights from oncoming cars. These symptoms most often dissipate over time and represent a small trade-off compared to the enhanced near vision. Some patients with the ReSTOR feel they need brighter light for the reading aspects to work well. Simple over-the-counter reading glasses alleviate this mild problem.

One cannot guarantee spectacle independence for distance. Very precise measurements are taken before the surgery and that information is inputted into very precise theoretical formulae to choose the power of the IOL. However, the final to-and-fro position of the IOL cannot be predicted as this depends upon healing, and this could cause one to not obtain the refractive goal. If so, this information is used as a fudge-factor when choosing the IOL power for the second eye and ultimately, good bilateral vision results. It is important to note that you ‘see with your brain, and not with your eyes,’ and even if each eye is slightly different, good vision is achieved. But keep in mind that if the final refractive result is less than desired, the fallback position is merely mild eyeglasses or LASIK surgery on the cornea. It is important to emphasize the concept that ultimately the measure of success is restoring the health of the eye.

Butterfly with cataracts and astigmatism

Vision affected by cataracts and astigmatism

butterfly with a traditional IOL and astigmatism

Vision after cataract surgery with a traditional IOL and astigmatism

Butterfly with ReSTOR or Toric-IOL

Vision with ReSTOR or Toric-IOL

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