For many people, the first sign of presbyopia is surprisingly ordinary.

The restaurant menu moves a little further away. Small print becomes easier in brighter light. The phone is still clear, but only if you hold it at just the right distance.

Eventually, reading glasses appear.

It can feel as though the eyesight has suddenly deteriorated. In reality, presbyopia is a normal age-related change in the eye’s ability to focus at near.

Understanding what is changing also helps explain why correcting presbyopia is different from simply correcting short-sightedness, long-sightedness or astigmatism.

How does a younger eye focus up close?

Behind the iris sits the eye’s natural crystalline lens.

In a younger eye, this lens can alter its focusing power when we move our attention from something in the distance to something close. This process is called accommodation.

You generally do not notice it happening.

Look across a room and the eye focuses for distance. Look down at your phone and the focusing system adjusts for near.

Over time, that ability declines.

What happens with presbyopia?

With age, the natural lens and the structures involved in focusing change. The eye gradually becomes less able to increase its focusing power for close work.

Presbyopia usually becomes noticeable during the 40s, although exactly when someone notices it depends on factors including their existing prescription and visual demands.

It then continues to progress for a period as the remaining accommodative ability decreases.

This is why someone who initially needs reading glasses only for very small print may later find them useful for more everyday near tasks.

Why do short-sighted people sometimes notice it differently?

A short-sighted person may be able to remove their distance glasses and read quite comfortably.

That can disguise some of the practical effects of presbyopia.

The eye has still lost accommodation, but the underlying myopia (short-sightedness) provides a near focal point when the distance correction is removed.

This becomes particularly important when discussing refractive surgery.

If a short-sighted patient has both eyes fully corrected for distance, the ability to simply remove their glasses to read is no longer available. Reading glasses may then become necessary.

The treatment has not created presbyopia. It has changed how the pre-existing presbyopia is experienced.

Why can’t ordinary laser eye surgery restore accommodation?

LASIK, SMILE and PRK alter the refractive power of the eye by changing the cornea.

Presbyopia originates from age-related changes involving the natural lens and the eye’s focusing system.

Reshaping the cornea can change where an eye focuses, but it does not make an ageing natural lens flexible again.

This distinction is important because advertising phrases such as “laser eye surgery for reading vision” can make the underlying mechanism sound simpler than it is.

There are refractive strategies that can reduce dependence on reading glasses, but they do not restore the accommodation of a young natural lens.

What is monovision?

One strategy is monovision sometimes also referred to as blended vision.

Instead of correcting both eyes to the same focal distance, one eye is principally targeted for distance while the other is left somewhat short-sighted to assist with nearer vision.

The visual system then uses information from the two eyes according to the task.

Some people adapt very well to this arrangement. Others do not like the difference between the eyes or notice an effect on depth perception or visual quality.

Where clinically appropriate, a contact lens trial can sometimes provide useful information about how a patient tolerates the proposed visual arrangement before surgery is considered.

Monovision is therefore an option, not a universal solution to presbyopia.

Where does refractive lens exchange fit?

As presbyopia progresses, particularly when the natural lens itself becomes increasingly relevant to the patient’s refractive problem, refractive lens exchange (RLE) may enter the discussion.

RLE involves removing the natural lens and replacing it with an artificial intraocular lens, or IOL.

You may also encounter terms such as PRELEX (Presbyopic Lens Exchange), Refractive Lens Replacement (RLR), Custom Lens Replacement (CLR), Lens Replacement Surgery, Refractive Lensectomy, Clear Lens Extraction (CLE), or Clear Lens Exchange (CLE).

Terminology varies, but these terms broadly describe lens-based refractive procedures in which the natural lens is removed and replaced with an intraocular lens primarily to alter the eye’s refractive state rather than because a visually significant cataract is necessarily present.

Does an artificial lens restore youthful focusing?

Not in the same way as a young natural lens.

Once the natural lens is removed, its remaining accommodation is also removed.

Different intraocular lens designs approach the problem in different ways.

Monofocal IOLs

A monofocal lens provides one principal point of focus.

If both eyes are targeted for distance, reading glasses will generally still be required. A monovision strategy can sometimes be used by targeting the two eyes differently.

Extended depth of focus IOLs

Extended depth of focus, or EDOF, lenses are designed to provide an extended range of useful vision, generally with an emphasis on distance and intermediate vision.

Reading glasses may still be required for smaller print or prolonged near work.

Multifocal and trifocal IOLs

Multifocal lenses use an optical design that provides more than one focal range.

Trifocal IOLs are a form of multifocal lens designed to provide principal focal ranges for distance, intermediate and near.

These lenses can reduce dependence on glasses across a broader range of activities, but they can also involve optical compromises such as halos, glare or differences in contrast and visual quality.

They do not recreate natural accommodation.

Why not simply replace the natural lens when presbyopia starts?

Because RLE is intraocular surgery.

For someone in their 40s whose natural lens remains clear and retains some accommodation, removing it is a very different proposition from putting on reading glasses.

RLE carries surgical risks and permanently removes the natural lens. The potential benefits therefore need to justify those considerations for the individual patient.

Age alone does not determine when RLE becomes appropriate.

Eye health, prescription, remaining accommodation, retinal considerations, visual requirements and the patient’s attitude to glasses and optical compromises all contribute to the decision.

For some patients, continuing with glasses or contact lenses is entirely reasonable.

What happens when cataracts eventually develop?

Presbyopia and cataract are both related to ageing of the natural lens, but they are not the same condition.

Presbyopia is the progressive loss of near focusing ability.

A cataract occurs when the natural lens becomes cloudy enough to affect vision.

Someone can therefore have significant presbyopia while their natural lens remains relatively clear.

If cataract surgery becomes appropriate later, the cloudy natural lens is removed and replaced with an IOL. At that point, the discussion about the desired range of vision and lens design becomes part of cataract treatment planning.

If the natural lens has already been removed during RLE, a cataract cannot subsequently form in that lens because it is no longer present.

The useful question is not simply “How do I get rid of reading glasses?”

Presbyopia affects almost everyone who reaches the appropriate age, but people experience it differently.

A person who spends eight hours a day at a computer has different visual priorities from someone whose main concern is night driving. Someone comfortable putting on reading glasses may view the compromises of surgery very differently from someone whose work makes glasses particularly inconvenient.

The aim of an assessment is therefore not simply to find a procedure capable of reducing reading-glasses dependence.

It is to understand;

• Which distances matter
• What compromises are acceptable
• What the eye is suitable for
• Whether intervention makes sense at all

That is a more useful starting point for discussing presbyopia.

Frequently Asked Questions

Is presbyopia the same as long-sightedness?

No. Long-sightedness, or hyperopia, is a refractive error related to how the eye focuses light. Presbyopia is an age-related reduction in the eye’s ability to change focus for near tasks. A person can have both.

Can presbyopia be prevented?

Presbyopia is associated with normal ageing of the eye’s focusing system. Reading glasses or refractive treatments can address its visual effects, but they do not prevent the underlying age-related change.

Does everyone eventually develop presbyopia?

Presbyopia is a normal age-related process. Existing refractive errors can change when and how its effects become noticeable.

Can LASIK fix reading vision permanently?

LASIK can alter corneal focusing power and can be used in strategies such as monovision, but it does not restore natural accommodation. The eye also continues to age after treatment.

Is RLE the same operation as cataract surgery?

The surgical principle is similar because both involve removing the natural lens and replacing it with an intraocular lens. The principal difference is the indication. Cataract surgery treats a cloudy natural lens, whereas RLE is performed primarily for refractive reasons when a visually significant cataract may not be present.

Does a trifocal lens work like a young natural lens?

No. A trifocal IOL uses an optical design intended to provide distance, intermediate and near focal ranges. It does not reproduce the natural accommodation of a young crystalline lens.

About the Specialist

Dr Peter Sumich is an ophthalmologist with a clinical focus on cataract surgery, laser vision correction and refractive lens exchange. His approach to refractive treatment planning considers the patient’s eye health, age, prescription and ocular measurements alongside how they use their vision in everyday life.

Related Articles

Refractive Lens Exchange: What Should Be Considered Before RLE?
How eye health, age, prescription, lifestyle and visual priorities influence whether lens-based refractive surgery may be appropriate.

Laser Eye Surgery in Your 40s: Why Reading Vision Changes the Discussion
Why presbyopia changes the treatment conversation when considering LASIK, SMILE or PRK.

Types of Intraocular Lenses (IOLs)
A practical explanation of monofocal, EDOF, multifocal, trifocal and toric intraocular lenses.

If changes in reading vision are becoming noticeable, a comprehensive eye and refractive assessment can help establish what is causing them and which options, if any, are appropriate for your individual eyes.

Disclaimer

This article provides general educational information only and does not constitute individual medical advice, diagnosis or treatment. Suitability for refractive treatment, expected outcomes, potential benefits, limitations, alternatives and risks depend on individual circumstances and require appropriate clinical assessment.

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