Lens Implant Selection: Dr. David Robinson on How Surgeons Choose

Choosing a lens implant is one of the key decisions in cataract surgery and refractive lens exchange (RLE). The lens a patient receives can affect how well they see at different distances for many years. 

The following questions and answers cover how Dr. David Robinson (a Sydney-based ophthalmic surgeon who specializes in cataract surgery, corneal surgery and refractive procedures) approaches lens selection and the factors patients should consider. 

How does cataract surgery differ from refractive lens exchange?

Both procedures involve removing the eye’s natural lens and replacing it with an artificial lens implant, called an intraocular lens (IOL). The difference is the reason for the surgery.

In cataract surgery, the lens is removed because it has become cloudy. In refractive lens exchange, the lens is removed to treat presbyopia, the normal age-related change that causes people to need reading glasses. Because both procedures replace the natural lens with an artificial one, they can be grouped together as lens implant surgery. The lens options below apply to both.

Why does the choice of lens matter so much?

Today there are many types of lens implants, each designed for different vision goals. This range of options can feel overwhelming for patients. The lens that is implanted can affect how well a patient sees for many years, including distance vision, reading, night driving, and computer work. For this reason, the decision deserves a careful, detailed discussion with the surgeon.

What should patients understand about vision before choosing a lens?

Two basic concepts make the lens options easier to understand: accommodation and visual zones.

Accommodation is the eye’s ability to autofocus. In younger people, the natural lens is flexible and changes shape to keep objects clear, both far away and up close. With age, the lens becomes stiffer and loses this flexibility. This loss of focusing ability is called presbyopia. Many people notice it in their 40s, and by their 50s or 60s, reading glasses are usually needed.

Visual zones describe the different distances at which the eyes are used:

• Near vision: About one foot away, such as reading or using a phone.
• Intermediate vision: About two to three feet away, such as using a computer, cooking, or looking at a car dashboard.
• Distance vision: Farther away, such as driving or watching television.

When a person can still accommodate, all three zones stay clear. As accommodation is lost, near and intermediate vision becomes blurry, which is why many people end up using bifocals or trifocals.

What are monofocal lenses?

A monofocal lens focuses on one distance. It does not correct astigmatism or presbyopia. Most patients who choose a monofocal lens have it set for distance vision, so glasses are usually needed for reading and computer work. Patients with astigmatism may also need glasses for distance vision.

The main advantage of monofocal lenses is that they are covered by Medicare and most insurance plans. The main drawback is continued dependence on glasses.

What are premium, or lifestyle, lenses?

Premium lenses include extended depth of focus (EDOF) lenses and multifocal or trifocal lenses. They are designed to provide a wider range of vision than a monofocal lens. Some provide distance and intermediate vision, while others also include near vision. The main benefit is less dependence on glasses.

What are the trade-offs of premium lenses?

Some patients notice halos, glare, or rings around lights at night. There may also be a small reduction in contrast or sharpness. Studies have reported that 95% to 97% of patients who chose these lenses would choose them again. Even so, Dr. David Robinson notes that premium lenses are not appropriate for every patient. They require healthy eyes and a healthy retina, which is why a detailed consultation is important.

What is a toric lens?

A toric lens corrects astigmatism. Astigmatism occurs when the front of the eye is shaped more like a football than a basketball, which can cause blurry or distorted vision. Toric lenses correct this during cataract surgery and can be used with either monofocal or premium lenses. The benefits are sharper vision and less need for glasses.

Are there other lens options?

Yes. The light adjustable lens is adjusted after surgery based on the patient’s glasses prescription. It requires several visits and a longer, specialized recovery process, so it is generally reserved for selected patients, such as those with unusual corneal shapes.

Mini monovision is another approach that may reduce the need for glasses. However, even with advanced lenses or mini-monovision, glasses may still be needed for small print.

What questions should patients ask themselves before choosing a lens?

Patients are encouraged to start with three questions:

1. Are my eyes healthy? Some advanced lenses work best in eyes without other eye diseases.
2. How important is freedom from glasses? Advanced lenses or mini monovision may reduce glasses use, but small print may still require glasses.
3. How much night driving do I do? Patients who drive often at night, or who are very sensitive to glare, may be better suited to simpler lenses. 

Is there one best lens for everyone?

No. The best choice depends on the patient’s eye health, daily activities, vision goals, and comfort with trade-offs. A vision lifestyle questionnaire can help guide this decision by showing how the patient uses their eyes each day. The most important step is a thorough consultation with an experienced eye surgeon who understands the patient’s goals.

Key Takeaway

Choosing a lens implant involves balancing vision goals with trade-offs. Monofocal lenses are usually covered by insurance, but glasses are often still needed. Premium lenses can reduce dependence on glasses but may cause halos, glare, or reduced contrast, and they require healthy eyes. Toric lenses can be added to correct astigmatism. 

According to Dr. David Robinson, the best choice depends on the patient’s eye health, daily activities, and vision goals. A thorough consultation is the most important step in selecting the right lens.

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