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Age-related long-sightednessPublished by Bupa's health information team, July 2008. This factsheet is for people who have age-related long-sightedness (presbyopia), or who would like information about it. Age-related long-sightedness happens when your eyes gradually lose the ability to focus on near objects. This makes tasks such as reading small print difficult. Its medical term is presbyopia. Almost everyone is eventually affected by presbyopia - it's a natural part of the ageing process. It usually begins at around the age of 40, and most people will need glasses or contact lenses by the time they are 45.
About age-related long-sightedness
Normal visionWhen you look at something, light rays from the object pass into your eye through the cornea - the clear structure at the front of your eye - then through the lens towards the retina at the back. In a healthy eye, the lens and cornea focus the light rays on a small area of your retina so that you can see the object clearly. The lens of your eye is naturally dome-shaped and very flexible. This allows you to focus from a range of distances, on objects far away and those that are very close up. To focus on near objects, the ciliary muscles at either side of the lens tighten causing it to change shape. This allows the lens to become thicker and more curved bringing light rays and close objects into sharp focus on the retina. This is called accommodation. To focus on objects in the distance, the lens returns to its natural resting state. Age-related long-sightedness or presbyopiaAs you get older your lenses slowly loses their flexibility, becoming less elastic and stiffer. This reduces the power of accommodation, and eventually light rays from near objects no longer focus on the retina. This makes close objects look blurred. There are five types of age-related long-sightedness.
Symptoms of age-related long-sightednessCommon symptoms of age-related long-sightedness include:
Causes of age-related long-sightednessPresbyopia is not a disease - it's the result of the normal, expected changes that happen to your lenses as you get older. It will affect almost everyone, regardless of whether you already wear glasses or contact lenses. As you would expect, the most common cause of presbyopia is ageing. Changes to the lens in the eye typically begin at the age of 40 and are completed by 60. By the age of 43, you may begin to notice changes in your vision (such as blurred or double print when reading). You may be at risk of developing presbyopia at a younger age (premature presbyopia) if you have a job that requires close up work or if you live in a hot climate with a high level of sun exposure. Also, being long-sighted (hypermetropic) and wearing corrective glasses or contact lenses is a common cause. Diagnosis of age-related long-sightednessAn optometrist (a health care professional who examines eyes, tests sight and dispenses glasses and contact lenses) will be able to diagnose presbyopia. They will focus especially on your near vision and will ask about any difficulties you have been having with your eyesight. Treatment for age-related long-sightednessGlasses and contact lensesPresbyopia can be corrected by wearing reading glasses or contact lenses. If you already wear glasses, you may be prescribed bifocal or varifocal lenses. These lenses will contain different strengths in different parts of the lens. For example, in bifocal lenses, the top half of the lens corrects for viewing distant objects whereas the bottom half corrects for near vision. If you already wear contact lenses, you may be prescribed bifocal contact lenses or reading glasses (as well as your contact lenses). Another option is monovison lenses, where one contact lens corrects for near vision and the other for distance vision. It's important to have check-ups with your optometrist every two years. This will ensure that your glasses or contact lenses stay the correct strength for you. SurgeryLens replacement surgeryLens replacement surgery can be used to treat presbyopia. This is when the lens in your eye is replaced with an artificial one. The procedure is called Presbyopic Lens Exchange (PRELEX) and uses a lens implant to replace your natural lens. This type of operation is usually performed under a local anaesthetic. This completely blocks feeling from the eye and you will stay awake during the operation. Scleral expansion surgeryScleral expansion surgery is a procedure that was used in the past to treat presbyopia. It involves making small incisions in the eye and inserting bands to stretch the part of the eye that controls focusing. However, the National Institute for Clinical Excellence (NICE) have recommended that this procedure should no longer be used as it has not proved to be effective and there are potential risks involved. Laser eye surgeryLaser eye surgery (such as LASIK) has been used to successfully treat long-sightedness for many years. However, it can't be used to treat presbyopia. Laser eye surgery changes the shape of the cornea to correct vision. As presbyopia is caused by changes in the responsiveness of your eye's lens, such treatment will have no effect. Further information
Related topicsSources
This information was published by Bupa's health information team and is based on reputable sources of medical evidence. It has been peer reviewed by Bupa doctors. The content is intended for general information only and does not replace the need for personal advice from a qualified health professional. Publication date: July 2008.
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