Ophthalmology

A cataract is a cloudy area in the lens of the eye that impairs vision. Cataracts often develop slowly and can affect one or both eyes. Symptoms may include faded colours, blurry or double vision, halos around light, trouble with bright lights, and difficulty seeing at night. This may result in difficulty driving, reading and recognizing faces. Poor vision caused by cataracts may also result in an increased risk of falling and depression. In 2020 Cataracts caused 39.6% of all cases of blindness and 28.3% of visual impairment worldwide. Cataracts remain the single most common cause of global bl

Ophthalmology (, ) is the branch of medicine that deals with the diagnosis, treatment, and surgery of eye diseases and disorders.

thumb|Blood vessels of the eyelids, front view

mammalian eye; part of the visual organ of the human body

second cranial nerve, which connects the eyes to the brain

thumb|upright=1.2|Wearing sunglasses under direct sunlight: Large lenses offer good protection, but broad temple arms are also needed against "stray light" from the sides.

cavity or socket of the skull in which the eye and its appendages are situated

4th cranial nerve

cranial nerve controlling the movement of the lateral rectus muscle

clarity of vision

focusing ability of eye

Miosis, or myosis (), is excessive constriction of the pupil. The opposite condition, mydriasis, is the dilation of the pupil. Anisocoria is the condition of one pupil being more dilated than the other.

Mydriasis is the dilation of the pupil, usually having a non-physiological cause, or sometimes a physiological pupillary response. Non-physiological causes of mydriasis include disease, trauma, or the use of certain types of drugs. It may also be of unknown cause.

paired, almond-shaped exocrine gland, one for each eye, that secretes the aqueous layer of the tear film

human disease

thumb|right|Rheum from a cat's eyes Rheum (; from Greek: ῥεῦμα rheuma 'a flowing, rheum') is a thin mucus naturally discharged from the eyes, nose, or mouth, often during sleep (contrast with mucopurulent discharge). Rheum dries and gathers as a crust in the corners of the eyes or the mouth, on the eyelids, or under the nose. It is formed by a combination of mucus (in the case of the eyes, consisting of mucin discharged from the cornea or the conjunctiva), nasal mucus, blood cells, skin cells, or dust.

fluid pressure inside the eye

Ketorolac, sold under the brand name Toradol, Acular and Sprix, among others, is a nonsteroidal anti-inflammatory drug (NSAID) used to treat pain. Specifically it is recommended for moderate to severe pain. Recommended duration of treatment is less than six days, and in Switzerland not more than seven days (parenterally two days). It is used by mouth, by nose, by injection into a vein or muscle, and as eye drops. Effects begin within an hour and last for up to eight hours. Ketorolac also has antipyretic (fever-reducing) properties.

total area or space visible in a person's peripheral vision with the eye looking straight forward

extent of the observable world seen at any given moment

type of laser

lens implanted in the eye to treat cataracts or myopia

medical specialty

type of craniofacial prosthesis

An eyepatch is a small patch that is worn in front of one eye. It may be a cloth patch attached around the head by an elastic band or by a string, an adhesive bandage, or a plastic device which is clipped to a pair of glasses. It is often worn by people to cover a lost, infected, or injured eye, but it also has a therapeutic use in children for the treatment of amblyopia. Eyepatches used to block light while sleeping are referred to as a sleep mask.

reflex controlling the diameter of the pupil in response to the intensity of light

alternative eyesight improvement therapy

upper, dilated end of the nasolacrimal duct

visual effect whose source is within the eye itself

transmissive optical device worn on the eye to improve visual perception

tetrachloro-tetraiodo-fluorescein used as stain

Pulse rate connected with eye muscles

a single layer of cells on the inner surface of the cornea

keratitis of the cornea that has material basis in herpes simplex type infection

pigmented hamartomatous nodular aggregate of dendritic melanocytes affecting the iris

disease of the eye in response to changes in the vitreous humor or more rarely, diabetes

human disease

thumb|An eye doctor examining a patient with a keratometer thumb|Typical presentations of keratoconus as detected through a keratometer thumb|Shin Nippon Nvision K-5001 Refkeratometer A keratometer, also known as an ophthalmometer, is a diagnostic instrument for measuring the curvature of the anterior surface of the cornea, particularly for assessing the extent and axis of astigmatism. It was invented by the German physiologist Hermann von Helmholtz in 1851, although an earlier model was developed in 1796 by Jesse Ramsden and Everard Home.

Neuro-ophthalmology is an academically-oriented subspecialty that merges the fields of neurology and ophthalmology, often dealing with complex systemic diseases that have manifestations in the visual system. Neuro-ophthalmologists initially complete a residency in either neurology or ophthalmology, then do a fellowship in the complementary field. Since diagnostic studies can be normal in patients with significant neuro-ophthalmic disease, a detailed medical history and physical exam is essential, and neuro-ophthalmologists often spend a significant amount of time with their patients.

tendency of the brain to prefer visual input from one eye over the other

tiny bright dots moving quickly in the visual field

type of eye-wear used to view the sun

Optotype

undereye makeup worn by sports players

A subluxation is an incomplete or partial dislocation of a joint or organ. According to the World Health Organization, a subluxation is a "significant structural displacement" and is therefore visible on static imaging studies, such as X-rays. Unlike real subluxations, the pseudoscientific concept of a chiropractic "vertebral subluxation" may or may not be visible on x-rays.

effects of blue light

reflex of the eye

A keratoscope, sometimes known as ''Placido's disk'', is an ophthalmic instrument used to assess the shape of the anterior surface of the cornea. A series of concentric rings is projected onto the cornea and their reflection viewed by the examiner through a small hole in the centre of the disk. A regular-shaped cornea should show equally spaced symmetric reflections. If the patient is suffering from astigmatism or from a corneal dystrophy, the rings will be distorted.

Osteo-odonto-keratoprosthesis (OOKP), also known as "tooth in eye" surgery, is a medical procedure to restore vision in the most severe cases of corneal and ocular surface patients. It includes removal of a tooth from the patient or a donor.

thumb|right|A phoropter can measure refractive error to determine an individual's spectacle lens prescription during an eye examination. thumb|right|Side of a phoropter that faces the patient

eye chart used to measure visual acuity

order written by an optometrist or ophthalmologist, specifying parameters of corrective lenses for a particular patient

disorder of lens

reflex action of the eye, in response to focusing on a near object, then looking at a distant object

cell type

Tebentafusp, sold under the brand name Kimmtrak, is an anti-cancer medication used to treat uveal melanoma (eye cancer). Tebentafusp is a bispecific gp100 peptide-HLA-directed CD3 T cell engager. Tebentafusp is given by intravenous infusion.

Spanish scientist, physicist and physiologist

A microkeratome is a precision surgical instrument with an oscillating blade designed for creating the corneal flap in LASIK or ALK surgery. The normal human cornea varies from around 500 to 600 μm in thickness; and in the LASIK procedure, the microkeratome creates an 83 to 200 μm thick flap. The microkeratome uses an oscillating blade system, which has a blade that oscillates horizontally as the blade travels vertically for a precise cut. This piece of equipment is used all around the world to cut the cornea flap. The microkeratome is also used in Descemet's stripping automated endothelial ke

Oil glands on the margin of the eyelid

thumb|A United States Navy optometrist technician using an autorefractor during a humanitarian assistance project in [[Nicaragua in 2008]] An autorefractor or automated refractor is a computer-controlled machine used during an eye examination to provide an objective measurement of a person's refractive error and prescription for glasses or contact lenses. This is achieved by measuring how light is changed as it enters a person's eye.