Presbyopia is a gradual loss of the eye's ability to focus on near objects, caused by the eye's natural lens stiffening with age. It is usually first noticed in the mid-40s and keeps progressing into the mid-50s, and it happens to almost everyone, including people who have already had successful laser vision correction.
What is happening to your eyes after 40 is not a disease and not a sign of damage. This page explains what has changed, what the options actually are, the corneal route and the lens route, and where each one's limits are.
Why choose us
The right route for you is not chosen by preference or by price. It is chosen by the state of your cornea, the state of your own natural lens, and your refraction. No page on the internet can determine that. An exam can.
Either the cornea's surface is reshaped with a laser while your natural lens stays exactly where it is, or your natural lens is replaced with an intraocular lens. The difference between the two is not price, it is the state of your natural lens and your age.
Before any surgical decision that relies on a deliberate difference between your two eyes, our practice is to have you trial the same setup with contact lenses for a period, so you find out for yourself whether you are comfortable with it.
Staying with reading glasses is a sound medical decision, not a failure and not a delay. For many people, after the exam, the right answer turns out to be no surgery at all.
We offer two routes, and the difference between them is not price and not personal preference. It comes down to two questions: is your own natural lens still clear, and how old are you, which is really a question of how long it is likely to stay clear.
| Criterion | Corneal route (laser) | Lens route (intraocular lens) |
|---|---|---|
| What changes | The cornea's surface is reshaped with a laser, your natural lens stays where it is | Your natural lens is removed and an intraocular lens that corrects near vision is implanted |
| State of your natural lens | Needs to still be clear | Makes sense once it has started to cloud |
| When it makes sense | A younger patient who wants to postpone any surgery inside the eye | An older patient who will need lens surgery within a few years regardless |
| If a cataract develops later | You will still need lens surgery, and IOL power calculation is harder on a cornea already reshaped by laser | Does not apply, the natural lens has already been replaced |
| Reversibility | A permanent change to corneal tissue, effectively not reversible | The lens can, in theory, be exchanged, but that is its own surgery with its own risks |
| Visual trade-off | Reduced distance sharpness in the eye set for near, and reduced depth perception | Halos, night glare, and reduced contrast with multifocal designs |
The lens route is explained in more detail on our premium IOL guide, and the laser route on our laser vision correction page.
The MEL 90 is an excimer laser from Carl Zeiss Meditec, used together with the VisuMax femtosecond laser that creates the flap. Its PRESBYOND Laser Blended Vision software does not add a second focal point the way multifocal lenses do. It reshapes the cornea with a non-linear profile that raises spherical aberration by a controlled amount, so each eye's depth of focus becomes a little wider than a single point.
The dominant eye is then set for distance and the other eye for about 1.50 dioptres of near. That offset is smaller than classic monovision, which usually uses 2.00 to 2.50 dioptres. Because each eye now covers a wider range, the two ranges overlap in the middle, the blend zone, and the brain keeps fusing both images instead of picking one eye. That is how the method tries to keep more depth perception and contrast than classic monovision.
Illustration of the blend-zone principle, drawn from how the method is described in the studies cited below, not from clinic measurements. In classic monovision (top) a gap remains between the two eyes at intermediate distance; in blended vision (bottom) the two ranges overlap.
A monofocal lens brings light to one point, so you see sharply at one distance. A trifocal lens splits light into three points, far, intermediate and near, and the price is that some light is lost between the points and halos appear around lights at night. An EDOF lens takes a third path: instead of several separate points, it stretches the single focus into a continuous range that starts at distance and extends through intermediate, the screen, the steering wheel, the kitchen counter, then fades gradually at very near.
The available designs reach that range in different ways: a diffractive design with fine rings, a non-diffractive design that shapes the wavefront, or a small aperture that works like a pinhole in a camera. In 2017 the American Academy of Ophthalmology set a common definition: to be called EDOF, a lens must see at 66 cm at least as well as a monofocal, and its depth of focus at the 20/40 level must be at least half a dioptre wider.
Illustration of the curve shapes as described in the studies cited below, not clinic measurements. The horizontal axis is the target distance expressed in dioptres, the vertical axis is visual acuity. The key point: EDOF holds a high level through intermediate and then falls, while a trifocal gives a third peak at near at the cost of dips between the peaks and more halos.
When is this route the logical one at our clinic? When the natural lens has already started to cloud, or when age makes lens surgery likely within a few years regardless. The natural lens is then removed by phaco and an EDOF or trifocal lens implanted according to your priorities, which our premium IOL page explains in detail.
In monovision, one eye, usually the dominant one, is set for distance, and the other eye is left or set for near, so the brain relies on whichever eye suits each distance. Many people who adapt to it stop noticing it within weeks.
Three things you should know before agreeing to it:
First, it is a trade-off, not a pure gain. The medical literature documents that it reduces stereo depth perception and binocular contrast quality when using both eyes together.
Second, some people never adapt to it and remain uncomfortable, and no exam can reliably identify those people beforehand.
Third, and the most practically important point: because no one can predict who will adapt, our practice is to have the patient trial the target setup with contact lenses for a period before any surgical step. We offer this as a practice we prefer, to reduce surprises, not as a test with a stated predictive accuracy.
This is not a formality. Every item here is a real reason to decline or postpone, and every item is written with its reason attached:
The exam typically takes 30 to 45 minutes. Contact lenses need to be stopped a week or two beforehand so the cornea returns to its natural shape, otherwise the measurements will not be accurate.
After the procedure: distance vision usually stabilizes before near vision does, and the balance settling between your two eyes takes longer. We advise patients not to judge their result in the first weeks, and follow-up extends past the third month, because presbyopia itself continues progressing with age.
Reading vision after forty
Choose the closest description
Distance is clear. Phone screens and print need reading glasses, and dim light makes it worse.
Your natural lens still does part of the work, so the choice depends on your prescription, your pupil size and what you read all day.
Both distances have slipped and the exam shows no significant cataract yet.
When both distances have gone, replacing the natural lens addresses them together. Which lens type suits you depends on your measurements and on how much night driving you do.
A cataract has been diagnosed and reading has become hard.
The implant that replaces the cataract also sets your focus for years afterwards. That decision belongs before surgery, not after it.
This guide points you in a direction. Your eye exam, your biometry and the retinal check decide which lens is appropriate.
Book a consultationCommon questions
Pick a day and time. The first visit is an eye exam with Dr. Ahmed Shaarawy, who tells you which option suits your eyes.
The next step is an exam that clarifies your own situation, not an appointment to schedule a procedure. Ask about everything on this page during it.
Holding your phone further away?
Drag the divider to see how things up close look with presbyopia and without it. Distance usually stays clear.
Read this text
Do you need to hold it further away?
Read this text
Do you need to hold it further away?
Near text blurs, so you hold the phone or book further away to read it
Small letters blur first, and it gets gradually worse with age
Distance usually stays clear, presbyopia affects near vision
Your exam decides what suits you, and that may simply be reading glasses. This picture is only an illustration.
