Region in the occiptal lobe of the brain where vision takes place. The anterior (front) portion provides peripheral vision and posterior central.
C (Calcarine Sulcus to Crystalline Lens)
An abnormal and uncontrollable growth of cells resulting in a tumour which can invade and destroy surrounding tissues spreading new cancers to other areas.
The most common eye cancer, a melanoma, is rare but early diagnosis is vital.
Clouding of the crystalline lens. Most people over 60 have some degree and is usually associated with growing old. Surgery will remove the cloudy lens and insert an artificial one.
Inflammatory lump in the meibomian gland which contributes towards the tear production and is located in the eyelid.
Layer between the retina and sclera (white of the eye) supporting the blood vessels which provide the retina with its oxygen and nutrition.
A growth, non-cancerous, in the choriod. Most never require treatment but if the growth leaks fluid or is found in the macula then treatment is necessary to aviod visual problems such as a retinal detachment.
Rare. Small can be treated but medium and large require either radiation therapy or complete removal of the eye.
Tumours can spread from other parts of the body to the eye or its surroundings. For women it is usually the breast and lung for men.
Rare. Similar to a raised freckle but found in the eye and should be investigated.
See intraocular lens.
With regard to the eye collagen is the protein fibrils in the cornea that help to maintain its shape. Some corrective surgery shrinks them to alter the shape and therefore the power of the cornea.
Hereditary. Incurable. Caused when the colour sensitive sensors (cones) fail to detect or send the required signals to the brain. Red/green is the most common blue/yellow more rare. Extremely rare is achromatopsia where there is no colour vision.
Prolonged use, due to the eyes being in a static position and the possibility of reduced blinking, can result in dryness a burning sensation focusing difficulty headaches and general blurred vision.
Light sensitive retinal cell responsible for colour and sharp central vision.
Loop of transparent membrane covering the white of the eye and the inner surface of the lids.
Pink eye. Inflamation of the conjunctiva caused by either bacteria ultraviolet exposure or a virus resulting in redness a discharge or a gritty feeling. In some cases contagious.
Optical correction resting on the front surface of the cornea. Can be either soft or rigid and have a life anywhere between one day and several years depending on the type.
Transparent structure found at the front of the eye through which can be veiwed the pupil and iris. It provides the major portion of the eye’s power while the crystalline lens alters in curvature to bring different distances into focus.
Although usually very painful the healing process is more rapid than most other body tissue.
Corneal clouding caused by a build up of abnormal material in the cornea. Can occur in old age and results in reduced vision.
A refractive surgery procedure where a prescription contact lens is inserted into the corneal tissue to correct shortsightedness (myopia).
See corneal topography.
Used in certain refractive surgery. Comprises of ring segments implanted in the corneal periphery intended to alter the corneal curvature and therefore its power. The rings can be either replaced or removed as necessary.
The mapping of the corneal surface with a computerised video camera. The information is used to assess the cornea and is particularly helpful during the pre refractive surgery evaluation.
Occurs when a break in the corneal surface becomes infected. Causes can include dryness an ingrowing eyelash or injury.
Otherwise known as strabismus. Eyes are misaligned pointing in different directions simultaneously. Usually a childhood condition but can continue into later life. Infant strabismus results in a loss of depth perception as the brain blocks one of the images. Adult strabismus, where none previously existed, produces double vision as the brain has adapted to the use of two superimposed images.
Situated behind the iris it is the eye’s focusing system responsible for changes in the depth of focus from distance to near and visa versa by altering in curature.