Eye Glossary

Accommodation: the process of refocusing nearby changing the inside working of an eye’s optical components. We lose this ability with aging (refer: Presbyopia). A person usually relaxes accommodation when seeing far.

Adie's Pupil: a pupil that fails to react to bright light normally due to impaired function of the nerve. There is no substantial interference to vision

Amaurosis Fugax: temporary blindness in one eye that may result from a transient ischemic attack (TIA) or an impending stroke

Amblyopia: also known as lazy eye, a misnomer, since what is “lazy” is not the eye but portions of the brain for eyesight; a visual impairment due to relative lack of inputs from the eye to the brain during childhood.

Amsler Grid: square grid with a dot at the centre used to diagnose macular degeneration (MD)

Anisometropia : a state of focus in such a way that the two-eye’s focus are different. If the anisometropia is significant enough, adults may get annoyed by it, and children can get amblyopia from it. If anisometropia is not large, it is often not a concern in adults and may even be beneficial

Aphakia: condition where the natural lens of the eye is missing, usually resulting from cataract extraction surgery

Arcus Senilis: grey or white ring that forms in the periphery of the cornea. There is no substantial interference to vision

Astigmatism: irregular shape of the eye’s focus in such a way that is akin to how a rugby ball’s focus would be shaped instead of a soccer ball’s, affecting clarity of objects at all viewing distances

Aqueous humour: clear fluid present between the cornea and lens, and maintains the pressure inside the eye

Bell's Palsy: condition which causes temporary paralysis of one side of the face, this can cause serious corneal problems from a loss of eyelid blinking on the same side

Blepharitis: inflammation of the eyelids causing red and itchy eyelids and formation of dry crusts on the eyelashes and poor tear quality

Blepharophimosis: shortened horizontal length of the eyelids

Canthus: Anatomic surrounding the junction of the upper and lower eyelids

Canthal Dystopia: Abnormally high or low canthus

Cataract: clouding of the natural lens of the eye and affects vision

Chalazion: a variable sized inflammatory cyst in the eyelid caused by blocked oil glands

Choroid: region between the sclera (white of the eye) and the retina that consists of the blood vessels and connective tissues

Ciliary body: tissue that produce aqueous humour

Ciliary muscle: helps change the shape of the lens for focusing of image

Conjunctiva: thin transparent membrane that coats the inner surface of the eyelid and the white part of the eyeball (the sclera)

Conjunctivitis: infection or inflammation of the conjunctiva

Cornea: dome-shaped clear circular window of the eye, in front of the iris and aqueous, and behind the tear film

Corneal Oedema: fluid collection in the cornea, often causing impairment of vision

Corneal Erosion: spontaneous loss of the outermost layer (epithelium) of the cornea which can cause sensitivity to light and blurring of vision

Corneal Ulcer: open sore in the outer layer of the cornea often caused by infection

Central Retinal Artery Occlusion: blockage of the main artery supplying blood to the retina

Central Retinal Vein Occlusion: blockage of the main vein in the retina

Central Serous Retinopathy: vision abnormality caused by build-up of fluid under the retina

Cyclophotocoagulation: procedure used to destroy the ciliary body, the part of the eye that produces fluid

Dacryocystitis: infection within the tear sac (nasolacrimal sac) adjacent to the nose

Dermatochalasis: excess skin on the eyelids, usually from loss of elastic tissue in the skin; also known as baggy eyes

Diplopia: double vision

Drusen: yellow deposits undertheretina; increases the risk of age-related macular degeneration

Distichiasis: growth of abnormal lashes towards the cornea

Ectropion: age-related abnormal outward turning of an eyelid

Entropion: abnormal inward turning of an eyelid causing redness and irritation

Epiblepharon: inward turning of turning of the eyelashes of the lower eyelid on looking down.

Epiretinal membrane: abnormal growth of thin transparent tissue on the surface of the macular area; also called macular pucker

Epiphora: overflow of tears onto the cheeks (watery eye)

Esotropia: condition where eye is turned inwards in relation to the other eye

Euryblepharon: sagging/retraction of the outer aspect of the lower eyelid

Exophthalmos: protrusion of eyeballs from their sockets, usually from a thyroid condition

Exotropia: condition where the eyes are turned outwards

Fluorescein angiography: test that uses a special dye and camera to observe the flow of blood in the retina and choroid

Fuchs' dystrophy: progressing disease characterised by the death of cells lining the cornea and maintaining its transparency

Glaucoma: damaged optic nerve caused by increased fluid pressure inside the eyes

Hemianopia: loss of vision in half of the visual field (in one or both eyes); often caused by brain injury or stroke

Hyphema: blood in the anterior chamber of the eye

Hypermetropia: (also known as Hyperopia) refer long-sightedness

Intraocular pressure: fluid pressure inside the eye

Iris: coloured part of the eye located between the cornea and lens which is responsible for regulating the amount of light that reaches the retina

Iridotomy: procedure which involves making a puncture through the iris

Iritis: inflammation of the iris

Keratitis: inflammation of the cornea

Keratectomy: removal of a portion of the cornea

Keratoconus: condition, in which the cornea takes a cone-like shape

Keratomileusis: procedure that corrects the curvature of the cornea

Lens: transparent flexible disc that helps focus light on the retina

Long-sightedness: condition which affects a person's ability to see objects close to them; also known as hyperopia

Macula: yellow central portion of the retina responsible for central high-resolution vision

Macular edema: fluid and protein deposition within the macula

Metamorphopsia: vision distortion in which straight lines seem wavy and parts central vision might be patchy

Micropsia: vision impairment in which objects appear to be smaller than normal

Myopia: short-sightedness. a state of relaxed focus such that near objects are clear, and distance objects blurry.

Neovascularisation: growth of small abnormal leaky blood vessels in the eye

Nystagmus: rhythmic involuntary repetitive movements of the eyes, usually horizontal side-to-side but can also be up-and-down or even rotatory

Ocular migraine: vision loss related to migraine, usually lasting less than an hour

Optic disc: the doughnut shaped disc which is the beginning of the optic nerve, shaped like a disc when viewed looking into the eyeball.

Optic nerve: nerve that connects the eye to the brain and passes on the information of the image to the brain

Optic neuritis: inflammation of the optic nerve resulting in visual disturbances

Optical coherence tomography: non-invasive imaging test that takes cross-sectional images of the retina

Papilloedema: swelling of the optic disc due to elevated fluid pressure in the brain

Periorbital: Eyelids and the immediate surrounding anatomical zone

Photodynamic therapy: a form of (now not so common) treatment for wet age-related macular degeneration (wet AMD)

Pinguecula: noncancerous growth of the conjunctiva, which is slightly raised from the surface of the sclera

Presbyopia: : age-related condition where the eye's lens loses its ability to change shape and position hence difficulty in focussing on nearby objects. In other words, loss of accommodation from age.

Pterygium: noncancerous growth that starts at the conjunctiva, covers the sclera, and grows onto the cornea; also known as Surfer’s eye

Ptosis: drooping of the eyelids

Retina: light-sensitive layer at the back of the eye

Retinopathy: disease of the retina

Retinal detachment: pulling away of the retina; potentially permanently sight-threatening if not re-attached.

Rubeosis iridis: growth of new abnormal blood vessels on the surface of the iris

Sclera: white of the eye

Scotoma: area of diminished vision within the visual field

Short-sightedness: refer myopia

Strabismus: misalignment of the eyes

Stye: small painful lump (collection of pus) at the base of the eyelashes usually caused by bacteria

Trichiasis: abnormal inward growth of normal lashes eyelash

Uvea: middle layer of the eye beneath the sclera, and consists of the iris, ciliary body, and choroid

Uveitis: inflammation of the uvea

Vitreous humour: clear gel-like material that lies between the lens and the retina

Vitrectomy: surgical removal of vitreous humour from the eye

Vitreous detachment: separation of vitreous humour from the retina