SHORT-SIGHTEDNESS | MYOPIA
DIFFICULTY WITH SEEING THINGS AT DISTANCE
What is short-sightedness, and can it be fixed?
In the normal eye, the cornea focuses light rays directly on the retina, resulting in clear vision without glasses or contact lenses.
In myopia, or short-sightedness, the eye is longer than normal. In some cases, the cornea may be more curved than normal.
The light rays go through the cornea but come together at a point in front of the retina, and are out of focus on the retina.
In short-sightedness, distant objects are blurred, while nearby objects can be clear.
You might be surprised that genetics is not the only factor in short-sightedness. Environmental factors also play a role. For example, short-sightedness almost doesn’t exist among members of traditional societies. As soon as you send children to school, however, about 40% of them develop this refractive error. It appears that there might be cells in the retina that respond to environmental demands of modern societies.
What is the best treatment for short-sightedness?
We use laser eye surgery (LASIK and ReLEx SMILE ™) to change the shape and curve of the cornea to correct or reduce these types of refractive errors. For patients in whom the cornea is not suitable for LASIK or SMILE ™ we can offer phakic IOL implantation. We can also use phakic IOLs to treat very high levels of short-sightedness.
SMILE ™ has been proven to be safe and effective for short-sightedness up to -10 dioptres. Dioptres are the units of focus in which your spectacle prescription is measured and documented. The spectacle prescription of the eye is 1 divided by the resting focal length of the eye measured in metres. So if the resting focal length of the eye is 50 centimetres (0.5metres) then the prescription of the eye is -2. Short sighted prescriptions have a minus sign at the beginning and long-sighted prescriptions have a plus sign.
SMILE ™ is the subject of research into treating higher prescriptions than -10. Phakic IOLs can comfortably treat up to -18 dioptres of short-sightedness. We have successfully treated patients with even higher prescriptions by combining phakic IOL implantation with LASIK laser surgery three months after the lens implantation.
Further information about short-sightedness
MORE USEFUL INFORMATION
Read more about laser eye surgery
New refractive surgery guidelines from The Royal College of Ophthalmologists, together with patient information on Laser Vision Correction, Phakic Intraocular Lens Implantation, Refractive Lens Exchange and a Checklist for patients will be published in April 2017. Click here for more information
Take this checklist to your consultation with your refractive surgeon performing the procedure. Discuss each item with your surgeon to help you make the decision that is right for you before having
refractive surgery. Click here for more information
The Royal College of Ophthalmologists’ Laser Vision Correction Patient Information booklet (PDF). Click here for more information
SMILE corrects myopia and astigmatism, or a combination of both refractive errors with only a very small incision at the corneal surface. This high-precision procedure is the latest development in the refractive laser treatments. Includes videos, treatment steps, and questions and answers.
Click here for more information
LASIK treats refractive errors by folding away the top layer of the eye and re-shaping tissue underneath. If a femtosecond laser is used, this type of procedure is called Femto-LASIK. Includes videos, treatment steps and questions and answers. Click here for more information
PRK/LASEK procedures remove a thin cell layer from the top of the eye so the laser can reshape the underlying cornea. This surgery may be an option for those who are not eligible for LASIK or those who look for the most economic option for refractive laser surgery. Includes videos, treatment steps, and questions and answers. Click here for more information
About the author
Mr James Ball | Consultant Ophthalmic Surgeon
MA (Cantab) MB BChir FRCOphth CertLRS
I am a Consultant Ophthalmic Surgeon at Custom Vision Clinic, St James’s University Hospital, and Nuffield Hospital. My major interest is in refractive surgery and finding the best treatment suitable for each patient.