Other common eye conditions are as follows:
ASTIGMATISM is a condition in which objects are blurred more in one direction than another and is caused by an irregular shape of the lens or the front surface (cornea) of the eye. It can be corrected by spectacles, contact lenses and refractive surgery. Astigmatism may occur together with myopia or hyperopia.
CATARACT is a condition in which the internal crystalline lens of the eye becomes less transparent with aging, making it more difficult for light to pass through to the retina. The loss of transparency may range from a slight cloudiness to a complete opacity. Cataract formation can change the power of the eye, alter the perception of colour and ultimately, if left untreated, cause blindness. Usually, both eyes are affected but not necessarily at the same rate. Cataract can be present in a new-born.
CONJUCTIVITIS is an inflammation of the conjunctival tissue of the eye that lines the surface of the eye-ball and the upper and lower lids. The most likely causes are infection (either bacterial or viral) and allergy.
DIABETIC RETINOPATHY (DR) is a condition that causes damage to the retinal tissue due to the associated complications of diabetes and occurs in a very high percentage of patients who have diabetes for a number of years. Poorly treated or untreated DR can cause blindness.
GLAUCOMA is an eye disease that damages the optic nerve and causes permanent vision loss in the affected eye(s). The nerve damage involves loss of retinal cells and occurs in a distinctive pattern. If left untreated it can result in blindness. Glaucoma is normally associated with raised fluid pressure (high tension) inside the eye. The term 'normal tension' (or 'low tension') glaucoma is used for those cases with optic nerve damage and visual field loss, but normal or low intraocular pressure (IOP). IOP is the only modifiable risk factor for glaucoma. However, some people may have high IOP for many years and never develop nerve damage, while others can develop significant damage at a relatively low pressure. Glaucoma can be roughly divided into two main categories, "open-angle" and "closed-angle" glaucoma. Closed-angle glaucoma can appear suddenly and is painful; visual loss can progress quickly, but the discomfort often leads patients to seek medical attention before permanent damage occurs. Open-angle (or chronic glaucoma) tends to progress at a slower rate and patients may not notice they have lost vision until the disease has progressed significantly.
HYPEROPIA is also known as long-sightedness. People with hyperopia have blurred near vision but distance vision may be clear. The hyperopic eye is shorter than the normal eye, meaning that light focuses behind the back of the eye (the retina) rather than on it, causing blurred vision. Hyperopia can be corrected with spectacles, contact lenses and refractive surgery.
MACULAR DEGENERATION (MD) is a condition that affects older people and causes significant loss of the central field of vision due to changes in the retina. MD is usually described as either ‘wet’ or ‘dry’ and is a leading cause of blindness in people over 50 years old.
PTERYGIA is a non-cancerous, triangular-shaped growth starting on the conjunctiva and extending onto the cornea. It is more likely found on the region of the eye near the nose but can also grow on the outer region. It is commonly associated with exposure to ultra-violet light, dust and dryness.
PINGUECULA is typically seen as a yellowish lump on the conjunctiva situated close to the corneal limbus but, unlike a pterygium, it does not grow or extend on to the cornea. It is commonly associated with exposure to ultra-violet light, dust and dryness. It generally does not cause any discomfort but may become inflamed when of significant size.
REFRACTIVE ERROR is a condition whereby the eye is unable to focus light on the retina. It is also known as ametropia and can be broadly classified as myopia (short-sight), hyperopia (long-sight) or astigmatism.
RETINOPATHY OF PREMATURITY (ROP) is an eye disease that can affect a baby born prematurely. ROP involves the abnormal growth of retinal blood vessels that may result in scar formation and ultimately retinal detachment causing blindness. Pre-term babies must be assessed for ROP.
TRACHOMA is an infection of the eye caused by a bacterium called Chlamydia trachomatis and results in a distinctive roughening (scarring) of the inner surface of the eyelid. The rough surface causes scarring of the cornea which ultimately leads to blindness.