How Does Laser Surgery Improve Vision?
Laser eye correction (LASIK or LASEK) is a surgical treatment for
people who want to reduce their dependence on glasses
or contact lenses. If you are dissatisfied wearing glasses
or contact lenses, then laser vision correction could
be for you.
Find out if LASEK or LASIK can help you restore your vision to normal sight.
| Figure 1 |
Figure 2 |
Figure 3 |
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Normal cornea |
After laser correction
for short-sight |
After laser correction
for long-sight |
Enjoy the freedom of natural vision
Imagine seeing clearly from the moment you open your eyes in the morning. Visualize yourself cruising effortlessly through your golf game without strain. Picture yourself walking confidently through your home when you have to get up with a little one in the early hours of the morning.
If fear of the unknown didn’t stand in the way, most people would make the choice to see clearly without the aid of glasses or contact lenses. Whether you are farsighted, nearsighted, or have astigmatism, laser vision correction could reduce or eliminate your dependence on glasses and contact lenses.
There are a few reasons to continue wearing glasses and contact lenses, but there are far more compelling reasons for wanting to get rid of them. The most common ones we hear are:
- My glasses steam up/streak with the weather
- I am intolerant of contact lenses and heavy glasses
- Maintaining my contact lenses is a bother
- I would like to feel more confident and attractive
- Sports are dangerous because of my glasses
- I would like to wake up and see without having to reach for my glasses
From golfing and swimming to driving and shopping, you could enjoy more freedom in your everyday life by restoring your natural vision. Gaining the freedom and security you want is actually quite easy. Laser vision correction is a pain-free process that takes only 20 minutes, and has less than 60 seconds of laser time per eyee
Who can benefit from laser eye surgery?
As a general rule, laser eye surgery can be beneficial to people who have poor vision due to an eye condition that can be corrected by wearing glasses, for example, short-sightedness. The surgery is not likely to benefit people who have an eye condition in which the vision cannot be improved by wearing glasses, for example, cataract or age-related macular degeneration. Read on to find out if laser eye surgery is the right choice for you.
We saw in About Your Eyes how the cornea focuses light onto the back of your eye. When you are shortsighted, the light gets bent inwards too much and the focus is too far forwards, inside the middle of the eye. Remember, light is bent by the cornea because it is curved. In shortsight, it is overly curved and so too powerful. If we want to bend the light rays less, we have to make the cornea flatter, not quite so powerful.
All of the treatments for shortsight aim to reduce the curve of the middle of the cornea. Operation such as the out-of-date radial keratotomy (RK) and the modern versions of laser vision correction all flatten the central part of your cornea, where most of the light goes through. In excimer laser surgery, the laser will remove more tissue from the centre of the cornea and less from the outside parts, as seen in Figure 2 below. Quite simply, we are shaving the top off. If exaggerated, the shape ends up looking something like a burger bun.
If you are longsighted, the cornea isn’t curved enough. It needs to be more powerful, so that the light rays are bent in more. This will bring the image forwards. Instead of being behind the eye, it will move up onto the retina (the light sensitive layer at the back of the eye, see About Your Eyes). To do this, we have to make the cornea more curved by removing tissue at the edges, all the way round, in a doughnut shape. The middle part of the cornea ends up more curved, as seen in figure 3.
| Figure 1 |
Figure 2 |
Figure 3 |
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Normal cornea |
After laser correction
for short-sight |
After laser correction
for long-sight |
The laser can remove tissue gently, without making any heat. We call it a cool laser beam. It is so precise it can remove only one quarter of a millionth of a metre with every pulse! Although there are different kinds of lasers they all will reshape your cornea, flattening for shortsight and steepening for longsight.
You can also correct astigmatism by selectively removing tissue from a band across the middle of the cornea. This will flatten or steepen the cornea only in one direction (axis), getting rid of the distortion caused by the astigmatism. This must be done very precisely; the computer will move the laser beam to exactly the right places to do this perfectly.
Find out more about the amazing technology used at Horizon Eye Centre London. WIth state of the art lasers and wavefront technology for selected eyes, you will see the difference for yourself!
If you want more information, please see out frequently asked questions
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