Short answer
PRELEX (Presbyopic Lens Exchange) replaces the eye’s aging natural lens with a premium artificial lens, restoring clear vision at near, intermediate and far distances. It is designed for adults aged 50 and over who depend on reading glasses because of presbyopia. Unlike laser surgery, which only reshapes the cornea, PRELEX treats the cause — and because the natural lens is removed, a cataract can never develop in that eye later in life.
Why do we need reading glasses after 50?
Reading glasses become necessary because the eye’s natural lens gradually loses its flexibility — a natural change called presbyopia that affects almost everyone.
When we are young, the lens changes shape hundreds of times a day, letting us focus effortlessly between distant and nearby objects. From around the age of 45 it begins to stiffen: restaurant menus seem harder to read, you hold your phone farther away, and by 50 reading glasses are often part of everyday life.
Presbyopia is not a disease, and no eye exercises or vitamins can reverse it. Unlike short- or long-sightedness, it is not caused by the shape of the eye or the cornea — the problem lies in the lens itself. That distinction determines which treatments can provide a lasting solution.
Why laser surgery cannot stop presbyopia
Laser vision correction changes only the cornea — it does not replace the aging natural lens.
LASIK remains an excellent option for younger adults with stable prescriptions. But because presbyopia continues to progress inside the eye, even patients with excellent laser results in their 30s or 40s often need reading glasses years later. PRELEX takes a different approach: it replaces the lens responsible for the loss of focusing ability. This is why it is increasingly recommended for suitable patients over 50.
What is PRELEX and how does it help?
PRELEX stands for Presbyopic Lens Exchange, also known as Refractive Lens Exchange (RLE): the surgeon removes the eye’s natural lens and replaces it with a premium intraocular lens (IOL).
The artificial lens does not age. Depending on the lens selected, patients can enjoy excellent vision for reading, computer work, driving and other everyday activities — the goal is to reduce or eliminate the need for glasses altogether. While no procedure can promise complete freedom from glasses for everyone, many people find they rarely need them after successful PRELEX surgery.
There is also a second, lifelong benefit: because the natural lens has been removed, a cataract cannot develop in that eye in the future. Many PRELEX patients therefore never need cataract surgery — they have already undergone essentially the same procedure, based on the same proven technique used in modern cataract surgery.
PRELEX vs. LASIK: what is the difference?
| PRELEX (Lens Exchange) | LASIK (Laser Surgery) | |
| How it works | Replaces the aging natural lens with a premium artificial lens. | Reshapes the cornea with a laser. |
| Best suited for | Adults aged 50+ with presbyopia. | Adults approximately 20–45 with stable prescriptions. |
| Near vision | Designed to improve both near and distance vision. | Near vision continues to decline as the natural lens ages. |
| Cataract prevention | Yes — cataracts cannot develop after lens replacement. | No — cataracts may still develop later in life. |
| Longevity | Permanent. Artificial lenses do not age. | Vision may gradually change as the natural lens ages. |
Which premium lenses are used for PRELEX?
Not all artificial lenses are the same — some prioritize reading vision, others intermediate vision for computer work, and some minimize glare during night driving. Among today’s leading premium intraocular lenses used across Europe are:
- ZEISS PureSee (EDOF) — one of the newest European premium lenses, designed for excellent contrast sensitivity with minimal halos.
- Alcon PanOptix — one of the world’s most widely implanted trifocal intraocular lenses.
- Johnson & Johnson TECNIS Odyssey — one of the newest full-range premium lenses, rapidly gaining popularity among European refractive surgeons.
- ZEISS AT LISA tri — a well-established European trifocal lens supported by extensive long-term clinical evidence.
There is no single “best” lens — the best lens is the one that fits your eyes, lifestyle and expectations, chosen after careful measurements and a detailed discussion with your surgeon.
Is PRELEX suitable for everyone?
No. The decision depends on the health of your retina and cornea, existing eye conditions, previous surgery, the strength of your prescription and your daily visual needs.
A responsible eye surgeon will always recommend the treatment with the safest and most predictable outcome — even if that means suggesting a different procedure instead of PRELEX. That is why every treatment plan begins with a comprehensive eye examination.
Key takeaways
- Presbyopia is caused by the aging of the eye’s natural lens and affects almost everyone from around age 45.
- Laser surgery reshapes only the cornea, so it cannot stop presbyopia from progressing.
- PRELEX replaces the natural lens with a premium artificial lens that never ages, restoring near, intermediate and distance vision.
- Because the natural lens is removed, PRELEX also prevents cataracts for life.
- Suitability must always be confirmed by a comprehensive eye examination.
Frequently asked questions
What is PRELEX?
PRELEX (Presbyopic Lens Exchange), also known as Refractive Lens Exchange (RLE), is a surgical procedure in which the eye’s aging natural lens is replaced with a premium artificial intraocular lens (IOL). It treats presbyopia at its source and is typically recommended for adults aged 50 and over.
Can LASIK fix presbyopia after 50?
Laser surgery such as LASIK reshapes only the cornea; it does not replace the aging natural lens. Because presbyopia is caused by the lens itself, even patients with excellent LASIK results in their 30s or 40s usually need reading glasses later. PRELEX replaces the lens responsible for the loss of focusing ability.
Does PRELEX prevent cataracts?
Yes. Because the natural lens is removed during PRELEX, a cataract cannot develop in that eye later in life. Many patients therefore never need cataract surgery, as PRELEX uses essentially the same surgical technique.
Coming up in Part 2
In Part 2 of this guide, we cover the practical side: how the operation is performed, what recovery is really like, possible risks, how to choose between today’s premium lenses — including current prices — and why the surgical philosophy of your eye surgeon can significantly influence your final result. We also introduce the meticulous, safety-first approach of Dr. Petr Novak, one of the Czech Republic’s highly experienced cataract and refractive surgeons.
About ROYAL MEDICAL
At ROYAL MEDICAL, we help international patients access leading eye specialists and premium eye surgery in Prague — coordinating every stage of the journey, from first consultation to final follow-up. If you are considering life without reading glasses, our team will be happy to help you find out whether PRELEX is the right solution for your eyes and your lifestyle.