Common eye conditions

Cataract
The crystalline lens of the eye should be clear. A cataract is the progressive clouding of this lens, blurring the vision. For the sufferer it's like looking out of a smeary or steamed-up window. Early cataracts are often accompanied by rapid refraction changes and increased glare sensitivity.Like presbyopia, cataract commonly occurs with ageing. Almost all people over 65 will have cataracts, however, only a small number will have poor vision as a result, and require an operation to remove the cataract. This is a surgical procedure, where the cloudy cataract lens is removed and a replacement (an intraocular lens or IOL) is usually inserted into the capsule at the same time, thus being able to restore clear vision without the necessity of thick glasses. Cataract surgery is now quite common place and has a high success rate.

Conjunctivitis
This is an inflammation of the conjunctiva and can be caused by dust and light, heat, irritant vapours, bacteria and viruses.

Signs are a red conjunctiva and swollen lids. Symptoms include intense ocular itching, grittiness and smarting. This common condition can be infectious and is usually treated with ointment or drops from your GP.

Colour vision anomalies
These are usually hereditary with around 8% of boys and less than 1% of girls having vision which is colour deficient. Boys are likely to be defective if their mother is a 'carrier' rather than if their father is colour deficient. Defective colour vision cannot be "cured" and it may be important when thinking about career options.

Detatched Retina
This is where the retina becomes detached from the back of the eye, frequently causing a sudden loss of vision. Other symptoms can be flashing lights and floaters. This is a serious condition requiring immediate referral to casualty for treatment.

Diabetes
In diabetes, changes can occur to the appearance of the retina. By checking, observing and monitoring any changes, the progress of the disease and how effectively it is being controlled, can be assessed by the optometrist.

Glaucoma
Glaucoma is caused by a progressive increase of the pressure in the eye to an abnormal level which damages the optic nerve so messages are no longer sent to the brain. This may lead to tunnel vision and blindness if not treated at an early stage.

If you suffer from diabetes, anemia, or hardening of the arteries or if you are black or have a family history of glaucoma, you are more likely to develop glaucoma.

There are two forms of glaucoma, chronic and acute.
• The acute form is where the pressure suddenly becomes very high and should be treated as soon as possible. It can be very painful.
• The chronic form is generally symptomless and is a gradual process. The pressure, whilst at an abnormally high level, does not get so high as to cause pain. The visual field is gradually affected.

Hypertension (High Blood Pressure
The retina is the only part of the body where both the arteries and veins can be readily seen. Hypertension causes changes to the blood vessels through out the body and these changes are the most obvious in the blood vessels of the retina.

Squint
This is when one eye turns and does not work properly with the other. The movements of the eyes are controlled by muscles which work in pairs. If one muscle is weak a squint can occur. A squinting eye may not develop properly leading to a 'lazy' eye. A child may have to wear a patch over the non-squinting eye to stimulate the vision in the poorer eye. Often an operation, sometimes followed by exercises, can remedy the squint. Early diagnosis is important.

Stye
A stye is caused when an eyelash follicle becomes infected. Most styes resolve themselves, although hot compresses can help. Also, medicated eye cleaning pads are now available that can help to accelerate the healing process.