Home » Encyclopedia » C (Calcarine Sulcus to Crystalline Lens)

C (Calcarine Sulcus to Crystalline Lens)

Calcarine sulcus

Wednesday, January 13th, 2010

Region in the occiptal lobe of the brain where vision takes place. The anterior (front) portion provides peripheral vision and posterior central.

Cancer

Wednesday, January 13th, 2010

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.

Cataract

Wednesday, January 13th, 2010

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.

Chalazion

Friday, January 15th, 2010

See Meibomianitis/Meibomitis.

Chalazion of the Eyelid

Wednesday, January 13th, 2010

Inflammatory lump in the meibomian gland which contributes towards the tear production and is located in the eyelid.

Choriod

Wednesday, January 13th, 2010

Layer between the retina and sclera (white of the eye) supporting the blood vessels which provide the retina with its oxygen and nutrition.

Choroidal Hemangioma

Wednesday, January 13th, 2010

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.

Choroidal Melanoma

Wednesday, January 13th, 2010

Rare. Small can be treated but medium and large require either radiation therapy or complete removal of the eye.

Choroidal Metastasis

Wednesday, January 13th, 2010

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.

Choroidal Nevus

Wednesday, January 13th, 2010

Rare. Similar to a raised freckle but found in the eye and should be investigated.

Clear Lens Extraction

Wednesday, January 13th, 2010

See intraocular lens.

Closed Angle Glaucoma

Wednesday, January 13th, 2010

See glaucoma.

Collagen

Wednesday, January 13th, 2010

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.

Colour Blindness

Wednesday, January 13th, 2010

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.

Computers

Wednesday, January 13th, 2010

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.

Cone

Wednesday, January 13th, 2010

Light sensitive retinal cell responsible for colour and sharp central vision.

Conjunctiva

Wednesday, January 13th, 2010

Loop of transparent membrane covering the white of the eye and the inner surface of the lids.

Conjunctivitis

Wednesday, January 13th, 2010

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.

Contact Lens

Wednesday, January 13th, 2010

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.

Cornea

Wednesday, January 13th, 2010

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.

Corneal Abrasion

Wednesday, January 13th, 2010

Although usually very painful the healing process is more rapid than most other body tissue.

Corneal Dystrophy

Wednesday, January 13th, 2010

Corneal clouding caused by a build up of abnormal material in the cornea. Can occur in old age and results in reduced vision.

Corneal Implants

Wednesday, January 13th, 2010

A refractive surgery procedure where a prescription contact lens is inserted into the corneal tissue to correct shortsightedness (myopia).

Corneal Mapping

Wednesday, January 13th, 2010

See corneal topography.

Corneal Ring

Wednesday, January 13th, 2010

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.

Corneal Topography

Wednesday, January 13th, 2010

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.

Corneal Ulcer

Wednesday, January 13th, 2010

Occurs when a break in the corneal surface becomes infected. Causes can include dryness an ingrowing eyelash or injury.

Cross Eyed

Wednesday, January 13th, 2010

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.

Crystalline Lens

Wednesday, January 13th, 2010

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.