Common eye conditions A brief overview of the six most common eye conditions. Expand Age-related Macular Degeneration Age-related macular degeneration (AMD) is a problem with your macula that causes sight distortion or loss to your central vision. It is not painful and it doesn't result in total sight loss. The exact causes are unknown but certain factors are thought to increase your chances of developing AMD such as smoking, sunlight, age and gender. The result of AMD is that when you look directly at something like the TV or photos, it causes a blurry patch in the middle of your vision which over time can become blank. Picture: Example of sight with AMD Diabetic retinopathy Diabetes is a condition where the amount of sugar in your blood is too high. To regulate the amount of sugar in your blood your body relies upon a hormone called insulin. Diabetes occurs when your body either produces very little or none of the hormone insulin (called Type 1 diabetes) or the insulin that is produced does not work properly or there isn’t enough of it (called Type 2 diabetes). Both types of diabetes can cause damage to tiny blood vessels in the back of the eye that supply the retina. This is called diabetic retinopathy. The blood vessels may swell and leak blood or fluid, or larger blood vessels may become blocked causing new, very weak blood vessels to grow in the wrong place on the retina. In very advanced cases, the retina can become detached. Diabetic retinopathy is very varied in severity. If mild and the blood vessels only swell or leak slightly, you may not notice any symptoms at all. If the blood vessels affected are on the macula, your central vision and ability to see detail will be affected. In the more advanced stages or if the diabetes isn’t controlled, blood vessels can bleed more severely and more suddenly obscuring patches of your sight where the bleeds occur. Total sight loss can occur in extreme cases. With diabetic retinopathy vision can change continually and unpredictably, even over the course of a day or within a day. This could mean a deterioration in sight or maybe just a change as the patches of obscurity move around. Picture: Example of sight with diabetic retinopathy Cataracts A cataract is a clouding of part of your eye called the lens. A common myth is that it is a layer of skin that grows over your eye. Many people over 60 have some cataract and the vast majority can be treated successfully. Early cataracts may not affect your sight and do not need treatment. Cataracts can form at any age. The most common type of cataract is age-related cataract and they develop as people get older. In younger people cataracts can result from conditions such as diabetes, certain medications and other longstanding eye problems. Cataracts can also be present at birth. These are called congenital cataracts. Cataracts causes vision to become blurred as the cataract is like a frosted glass interfering with your sight. Picture: Example of sight with cataracts Glaucoma Glaucoma is the name given to a group of eye conditions which cause damage to the optic nerve. This damage can be caused by increased pressure in the eye damaging the optic nerve, or by a weakened optic nerve, or often by a combination of the two. This high pressure in the eye is not linked to blood pressure. It is caused when drainage channels in the eye become blocked and there is a build-up of fluid in the eye. There are different types of Glaucoma depending upon the speed at which the drainage channels become blocked or whether another eye condition has caused the Glaucoma. In very rare cases babies can have Glaucoma caused by a malformation of the eye. Glaucoma can develop very slowly and may be symptom-free at first. Left to develop untreated it can cause loss of your side (peripheral) vision leaving you only able to see things directly in front of you (tunnel vision). Picture: Example of sight with glaucoma Retinitis Pigmentosa Retinitis Pigmentosa (RP) is the name given to a group of inherited diseases of the retina that all lead to a gradual progressive reduction in vision. The age at which symptoms start is variable and may vary with the different genetic types. The rate at which vision deteriorates is also variable but is generally very slow with changes occurring over years rather than months. In approximately half of all cases (50 to 60%) there are other family members with RP. Difficulties with night vision and peripheral vision are usually the first things that are noticed. Later, reading vision (detailed vision) and colour vision are usually affected and eventually some people may become blind. Picture: Example of sight with RP Charles Bonnet Syndrome Charles Bonnet Syndrome (CBS) is a common condition among people who have lost their sight. It causes people who have lost a lot of vision to see things that aren't really there, known as visual hallucinations. CBS can be distressing but the hallucinations are usually not permanent. Many people experience hallucinations for a year to eighteen months before they become a lot less frequent.