How does laser eye surgery work?

If you wear glasses or contact lenses every day, you have probably wondered what laser eye surgery actually does. People often hear words like “laser,” “cornea,” or “reshape,” and it can feel technical fast. This blog breaks it down in plain language so you can understand what happens, why it works, and what the process usually looks like.

First, what is the problem being treated?

Most people who consider laser eye surgery have a refractive error. That is just a focusing problem.

• Short sight (myopia): you see up close well, but distance is blurry.
• Long sight (hyperopia): distance may be clearer, but close work can be hard.
• Astigmatism: vision can be distorted or blurry because the eye is shaped more like a rugby ball than a soccer ball.

In all of these, light does not focus neatly on the back of the eye (the retina). The goal is to help light focus more accurately.

The cornea is the “front window” of your eye

Laser eye surgery mainly treats the cornea, the clear front part of the eye. Think of it like a camera lens. If you change the shape of that front window by tiny amounts, you change how the eye focuses light.

Laser eye surgery does not put a laser inside your brain or “burn” the eye. It uses a very controlled beam of light to remove microscopic layers of corneal tissue. The aim is to change the curve of the cornea so the eye focuses better.

How does the laser reshape the cornea?

The most common lasers used are called excimer lasers. They remove tiny amounts of tissue with very high precision. The amount removed is measured in microns (millionths of a metre). It is so small you cannot see it with the naked eye.

A computer-guided treatment plan is created using your eye measurements. The laser then follows that plan during the procedure. This is why the assessment is important. The better the measurements, the better the plan.

What are the main types of laser eye surgery?

Different clinics may offer different options, but the most common are:

LASIK

LASIK involves creating a thin flap in the cornea, lifting it, reshaping the tissue underneath with the laser, and then placing the flap back. The flap acts like a natural bandage while the surface heals.

SMILE® Pro

SMILE® Pro is another type of laser vision correction. Unlike LASIK, it does not involve creating a large corneal flap. Instead, a femtosecond laser creates a small disc of tissue (often called a lenticule) inside the cornea. That lenticule is then removed through a small opening. This changes the cornea’s shape so light can focus more clearly. SMILE® Pro is commonly used for short sight (myopia) and sometimes astigmatism, but suitability depends on your prescription and eye measurements.

PRK (or surface laser)

PRK reshapes the cornea from the surface. The thin outer skin of the cornea (the epithelium) is removed first, then the laser reshapes the surface underneath. The epithelium grows back over time. PRK often has a longer early recovery than LASIK or SMILE® Pro.

Your surgeon recommends the approach based on your eye health, corneal thickness, prescription, and lifestyle needs.

What happens at the assessment?

The assessment is where you get clear answers on suitability and options. It usually includes:

• A detailed eye health check
• Measurements of corneal shape and thickness
• Prescription testing
• A check for dry eye and other surface issues
• Discussion about your work, hobbies, screens, and driving

This is also where you talk about what you want. Some people care most about distance vision. Some care about sport. Some care about comfort with contact lenses. The assessment is where you work out what is realistic for your eyes.

What happens on the day of treatment?

Exact steps vary by procedure, but the overall experience is often like this:

1. Numbing drops are used so you should not feel sharp pain.
2. You lie under the laser.
3. A device gently holds the eyelids open.
4. You look at a light while the laser treatment is delivered.
5. The laser portion is usually short.
6. You rest briefly afterwards and go home the same day.

Most people are surprised by how quick the laser part is. Your team will guide you through each step as it happens.

How does healing work?

Healing depends on the type of procedure.

• With LASIK, early comfort and visual recovery are often quicker because the surface is less disturbed.
• With SMILE® Pro, there is no large corneal flap. Instead, the treatment is performed through a small opening in the cornea. Many people notice vision improving in the first days, with ongoing settling as healing continues. Dry eye symptoms and visual effects like glare or halos can still occur, especially early on, and recovery timelines vary by person.
• With PRK, the surface needs time to regrow and settle, so recovery is often more gradual.

Either way, it is normal for vision to fluctuate while healing. Dry eye symptoms can also happen, especially early on. Follow-up visits help your surgeon monitor healing and guide you on drops and activity.

What about safety and suitability?

Laser eye surgery is not for everyone. A safe plan starts with screening and honest advice. Things like corneal thickness, dry eye, and certain eye conditions can affect whether laser treatment is suitable, or which type is safer.

That is why clinics that focus on careful testing and planning matter. The goal is not to “fit everyone in.” The goal is to treat the right people, in the right way, at the right time.

A simple next step

If you are curious but not ready to book anything, start small.

Take our free suitability self-test. It takes about 2 minutes and helps you explore which options may suit your eyes and lifestyle.