LASIK - Laser Eye Surgery

What is LASIK?

LASIK is a type of laser eye surgery treatment that uses a laser to correct many common vision problems such as myopia, hyperopia and astigmatism. It stands for laser assisted in situ keratomileusis and is performed by ophthalmologists and aided by a computer.

The procedure became common practice in 1992, evolving from the previous operation known as PRK or photo refractive keratectomy. Today’s LASIK operation differs in a number of ways from the original procedure, having faster recovery times with less associated pain.


There are two main types of LASIK procedure. Normal LASIK uses a microkeratome to produce a flap in the cornea before a laser is used to thin it out. This is opposed to the newer ‘bladeless’ LASIK which uses only lasers throughout the operation.

Can I have LASIK surgery?

You are suitable for this procedure if you are over 21 years old and your prescription has been stable for over two years. Owing to the nature of the treatment, if your cornea is too thin your ophthalmologist will suggest you have a different operation such as Epi-LASIK. It is important to note that this laser procedure doesn’t correct presbyopia. There are other operations such as laser blended vision and conductive keratoplasty, which are covered in another section of this guide.

How is the LASIK surgery carried out?

Prior to the operation a map of the cornea is made using a corneal topographer. This enables the ophthalmologist to adequately determine how much corneal tissue is needed to be removed in different areas of the eye. This map is combined with other information such as the thickness of the cornea to produce a final representation of the cornea, so the surgeon has something to work towards.

Before the LASIK procedure starts, the surgeon will get you to lie down on a bed or sit in a chair, at which point anaesthetic eye drops will be put in your eye to prevent any pain that could occur during the procedure. Sometimes mild sedative drugs are used to cause relaxation, as you will be awake for the entire time. This also helps you to remain still as the ophthalmologist operates on your eye. To prevent you from blinking during the operation, a device like a clamp will be used to keep your eye open.

The LASIK procedure can be roughly split into three specific parts. The first entails creating a flap in the front of the cornea, the second uses a laser to remove the underlying tissue whilst the third involves placing the corneal flap back in the right position.

The cornea has an outer membranous coating that protects the delicate tissue underneath it. In some surgical treatments, for example PRK, this membrane can be sliced off to help correct problems with vision. LASIK vision correction relies on removing tissue from under the membrane as it does not regenerate. This gives lasting vision correction.

In standard LASIK procedures, prior to cutting a flap in the cornea, a suction cap is applied to the front of the eye to hold the eye steady (this is removed after the flap is cut). Once fixed, the ophthalmologist will ask you to look at a coloured light as they create a flat in your cornea using a piece of equipment called a microkeratome. This is in essence a very sharp knife that vibrates quickly, allowing it to cut extremely thin flaps in the cornea very accurately. A hinge is left at one end of the flap, ensuring it can be repositioned at a later stage. You may find that you may experience a little discomfort at this stage, this is entirely normal. By opening the front membrane of the cornea, the ophthalmologist can expose the stromal layer beneath it. It is this layer that is remodelled to help correct our vision.

Once the stroma has been exposed, it is likely that your vision will become very cloudy and blurry. Don’t worry, this is common when the flap is removed as your eye can no longer focus the light. At this point, the ophthalmologist uses a specialised laser to vaporise specific parts of the stroma. This process is very safe and requires no burning of the cornea. The laser removes a very small number of cells every time, usually in bursts around one 15th of a second! It is targeted to very specific areas of the stroma by a computer, which corrects the location of the laser pulse depending upon the movement of the eye. This ensures no mistakes are made during this stage of the operation. Using a laser instead of a microkeratome in this process ensures very accurate results and also decreases the recovery time after the procedure.

Following stroma remodelling, the ophthalmologist replaces the flap of corneal tissue onto the front of the eye. They will then check to make sure there are no air bubbles or material under the flap that can cause problems after the operation. The flap of tissue will stay stuck to the stromal layer and will heal naturally after the procedure. If you are having both eyes operated on, they are usually done one after the other, even sometimes on separate days. This applies for all laser eye surgery procedures.

What happens after LASIK surgery?

After the procedure, you will be given eye drops that contain both antibiotics to prevent any infections in your eye and agents that prevent your eye from becoming too swollen up. It is also important in the days following surgery that you get enough rest and don’t expose your eyes to too much light. Many laser eye surgery clinics will provide you with some goggles that look like sunglasses to wear outside. It is also recommended that you try to not rub your eye, instead you should keep it regularly lubricated with artificial tears. Your ophthalmologist will want to see you in the first 48 hours after the operation to make sure that your eye is healing well enough. Further information about the recovery period and what to expect after the operation is available in another part of this guide.

You should expect your vision to return to normal within the first few days after the procedure however this can take up to a week, after which you should be free of corrective eyewear or at least less dependent in glasses/contact lenses! Studies have shown that patients who had the procedure when it was first introduced in 1992 are still enjoying good eyesight. The procedure takes little over 40 minutes and some patients even report seeing a marked improvement straight after the surgery has been done, with over 95% of patients being happy with the end result. It is important that you know and understand what can happen if the procedure doesn’t go to plan, read Risks involved in Laser Eye Surgery.

How much does LASIK cost?

Prices for LASIK vary depending on the clinic and the type of surgery you have. The standard procedure costs on average around £300 cheaper than the bladeless version. The LASIK operation also costs more if you decide to have it with wavefront or wavelight guided technology. Usually, the cost of LASIK starts at around £1000 per eye.

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