An eye examination is a battery of tests performed by an ophthalmologist, optometrist, or orthoptist assessing vision

Visual perception

Visual perception is the ability to interpret information and surroundings from the effects of visible light reaching the eye. The resulting perception is also known as eyesight, sight, or vision...

 and ability to focus

Focus (optics)

In geometrical optics, a focus, also called an image point, is the point where light rays originating from a point on the object converge. Although the focus is conceptually a point, physically the focus has a spatial extent, called the blur circle. This non-ideal focusing may be caused by...

 on and discern objects, as well as other tests and examinations pertaining to the eye

Human eye

The human eye is an organ which reacts to light for several purposes. As a conscious sense organ, the eye allows vision. Rod and cone cells in the retina allow conscious light perception and vision including color differentiation and the perception of depth...

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Health care professionals often recommend that all people should have periodic and thorough eye examinations as part of routine primary care, especially since many eye diseases are asymptomatic.

Eye examinations may detect potentially treatable blinding

Blindness

Blindness is the condition of lacking visual perception due to physiological or neurological factors.Various scales have been developed to describe the extent of vision loss and define blindness...

 eye diseases, ocular manifestations of systemic disease, or signs of tumours or other anomalies of the brain

Brain

The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,...

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• External examination
• Visual acuity
  Visual acuity
  Visual acuity is acuteness or clearness of vision, which is dependent on the sharpness of the retinal focus within the eye and the sensitivity of the interpretative faculty of the brain....
  
  
• Amplitude of accommodation
  Amplitude of accommodation
  Amplitude of accommodation is a measurement of the eye’s ability to focus clearly on objects at near distances . This eye focusing range for a child is usually about 5–7.5 cm . For a young adult, it is 10–15 cm . The focus range for a 45-year-old adult is about 50 cm...
  
  
• Color vision
  Color vision
  Color vision is the capacity of an organism or machine to distinguish objects based on the wavelengths of the light they reflect, emit, or transmit...
  
  
• Cover test
  Cover test
  A cover test is an objective determination of the presence and amount of ocular deviation. It is typically performed by orthoptists, ophthalmologists and optometrists during eye examinations....
  
  
• Stereopsis
  Stereopsis
  Stereopsis refers to impression of depth that is perceived when a scene is viewed with both eyes by someone with normal binocular vision. Binocular viewing of a scene creates two slightly different images of the scene in the two eyes due the the eyes' different positions on the head...
  
  
• Near point of convergence
• Extraocular motilities
• Pupil
  Pupil
  The pupil is a hole located in the center of the iris of the eye that allows light to enter the retina. It appears black because most of the light entering the pupil is absorbed by the tissues inside the eye. In humans the pupil is round, but other species, such as some cats, have slit pupils. In...
  
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• Visual field
  Visual field
  The term visual field is sometimes used as a synonym to field of view, though they do not designate the same thing. The visual field is the "spatial array of visual sensations available to observation in introspectionist psychological experiments", while 'field of view' "refers to the physical...
  
   screening
• Interpupillary distance

• Lensometry
• Keratometry
• Retinoscopy
  Retinoscopy
  Retinoscopy is a technique to obtain an objective measurement of the refractive error of a patient's eyes. The examiner uses a retinoscope to shine light into the patient's eye and observes the reflection off the patient's retina...
  
  
• Refractional
• Monocular
• Binocular balance
• Cycloplegic refraction

• Accommodative
  Accommodation (eye)
  Accommodation is the process by which the vertebrate eye changes optical power to maintain a clear image on an object as its distance changes....
  
   system
• Negative relative accommodation
  Negative relative accommodation
  Negative relative accommodation was proposed by Prof. Joseph Kearney of Oxford University in 1967, is a measure of the maximum ability to relax accommodation while maintaining clear, single binocular vision. This measurement is typically obtained by an orthoptist, ophthalmologist or optometrist...
  
  
• Positive relative accommodation
  Positive relative accommodation
  Positive relative accommodation is a measure of the maximum ability to stimulate accommodation while maintaining clear, single binocular vision. This measurement is typically obtained by an orthoptist, ophthalmologist or optometrist during an eye examination using a phoropter...
  
  
• Vergence
  Vergence
  A vergence is the simultaneous movement of both eyes in opposite directions to obtain or maintain single binocular vision..When a creature with binocular vision looks at an object, the eyes must rotate around a vertical axis so that the projection of the image is in the centre of the retina in both...
  
   system
• Optokinetic system

• Slit lamp
  Slit lamp
  The slit lamp is an instrument consisting of a high-intensity light source that can be focused to shine a thin sheet of light into the eye. It is used in conjunction with a biomicroscope...
  
   biomicroscopy

• Binocular indirect ophthalmoscopy
• Tonometry
  Tonometry
  Tonometry is the procedure eye care professionals perform to determine the intraocular pressure , the fluid pressure inside the eye. It is an important test in the evaluation of patients at risk from glaucoma...
  
  
• Amsler grid
  Amsler grid
  The Amsler grid, used since 1945, is a grid of horizontal and vertical lines used to monitor a person's central visual field. The grid was developed by Marc Amsler, a Swiss ophthalmologist. It is a diagnostic tool that aids in the detection of visual disturbances caused by changes in the retina,...
  
  
• Visual field
  Visual field
  The term visual field is sometimes used as a synonym to field of view, though they do not designate the same thing. The visual field is the "spatial array of visual sensations available to observation in introspectionist psychological experiments", while 'field of view' "refers to the physical...
  
   assessment
• Gonioscopy
  Gonioscopy
  Gonioscopy describes the use of a goniolens in conjunction with a slit lamp or operating microscope to gain a view of the iridocorneal angle, or the anatomical angle formed between the eye's cornea and iris...
  
  

• Corneal topography
  Corneal topography
  Corneal topography, also known as photokeratoscopy or videokeratography, is a non-invasive medical imaging technique for mapping the surface curvature of the cornea, the outer structure of the eye...
  
  
• Corneal pachymetry
  Corneal pachymetry
  Corneal pachymetry is the process of measuring the thickness of the cornea using contact methods, such as ultrasound and confocal microscopy , or noncontact methods such as optical biometry with a single Scheimpflug camera , or a Dual Scheimpflug camera , or Optical Coherence Tomography and online...
  
  
• Scheimpflug ocular imaging
• Retinal tomography
• Ocular computed tomography
  Computed tomography
  X-ray computed tomography or Computer tomography , is a medical imaging method employing tomography created by computer processing...
  
  
• Scanning laser polarimetry
  Scanning laser polarimetry
  Scanning laser polarimetry is the use of polarised light to measure the thickness of the retinal nerve fiber layer as part of a glaucoma workup. The GDx-VCC is one example....
  
  

Corneal pachymetry

Corneal pachymetry

Corneal pachymetry is the process of measuring the thickness of the cornea using contact methods, such as ultrasound and confocal microscopy , or noncontact methods such as optical biometry with a single Scheimpflug camera , or a Dual Scheimpflug camera , or Optical Coherence Tomography and online...

 is a measurement of the thickness of the cornea

Cornea

The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber. Together with the lens, the cornea refracts light, with the cornea accounting for approximately two-thirds of the eye's total optical power. In humans, the refractive power of the cornea is...

 using ultrasound

Ultrasound

Ultrasound is cyclic sound pressure with a frequency greater than the upper limit of human hearing. Ultrasound is thus not separated from "normal" sound based on differences in physical properties, only the fact that humans cannot hear it. Although this limit varies from person to person, it is...

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Ideally, the eye examination consists of an external examination, followed by specific tests for visual acuity

Visual acuity

Visual acuity is acuteness or clearness of vision, which is dependent on the sharpness of the retinal focus within the eye and the sensitivity of the interpretative faculty of the brain....

, pupil

Pupil

The pupil is a hole located in the center of the iris of the eye that allows light to enter the retina. It appears black because most of the light entering the pupil is absorbed by the tissues inside the eye. In humans the pupil is round, but other species, such as some cats, have slit pupils. In...

 function, extraocular muscle

Extraocular muscles

The extraocular muscles are the six muscles that control the movements of the eye . The actions of the extraocular muscles depend on the position of the eye at the time of muscle contraction.-List of muscles:-Importance:...

 motility, visual field

Visual field

The term visual field is sometimes used as a synonym to field of view, though they do not designate the same thing. The visual field is the "spatial array of visual sensations available to observation in introspectionist psychological experiments", while 'field of view' "refers to the physical...

s, intraocular pressure

Intraocular pressure

Intraocular pressure is the fluid pressure inside the eye. Tonometry is the method eye care professionals use to determine this. IOP is an important aspect in the evaluation of patients at risk from glaucoma...

 and ophthalmoscopy

Ophthalmoscopy

Ophthalmoscopy is a test that allows a health professional to see inside the fundus of the eye and other structures using an ophthalmoscope . It is done as part of an eye examination and may be done as part of a routine physical examination...

 through a dilated pupil.

A minimal eye examination consists of tests for visual acuity, pupil function, and extraocular muscle motility, as well as direct ophthalmoscopy through an undilated pupil.
External examination of eyes consists of inspection of the eyelid

Eyelid

An eyelid is a thin fold of skin that covers and protects an eye. With the exception of the prepuce and the labia minora, it has the thinnest skin of the whole body. The levator palpebrae superioris muscle retracts the eyelid to "open" the eye. This can be either voluntarily or involuntarily...

s, surrounding tissue

Tissue (biology)

Tissue is a cellular organizational level intermediate between cells and a complete organism. A tissue is an ensemble of cells, not necessarily identical, but from the same origin, that together carry out a specific function. These are called tissues because of their identical functioning...

s and palpebral fissure

Palpebral fissure

Palpebral fissure is the anatomic name for the separation between the upper and lower eyelids. In adults, this measures about 10mm vertically and 30mm horizontally.It can be reduced in horizontal size by fetal alcohol syndrome and in Williams Syndrome...

.
Palpation of the orbital rim may also be desirable, depending on the presenting signs and symptoms.
The conjunctiva

Conjunctiva

The conjunctiva covers the sclera and lines the inside of the eyelids. It is composed of rare stratified columnar epithelium.-Function:...

 and sclera

Sclera

The sclera , also known as the white or white of the eye, is the opaque , fibrous, protective, outer layer of the eye containing collagen and elastic fiber. In the development of the embryo, the sclera is derived from the neural crest...

 can be inspected by having the individual look up, and shining a light while retracting the upper or lower eyelid.
The cornea

Cornea

The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber. Together with the lens, the cornea refracts light, with the cornea accounting for approximately two-thirds of the eye's total optical power. In humans, the refractive power of the cornea is...

 and iris

Iris (anatomy)

The iris is a thin, circular structure in the eye, responsible for controlling the diameter and size of the pupils and thus the amount of light reaching the retina. "Eye color" is the color of the iris, which can be green, blue, or brown. In some cases it can be hazel , grey, violet, or even pink...

 may be similarly inspected.
Visual acuity is the eye's ability to detect fine details and is the quantitative measure of the eye's ability to see an in-focus image at a certain distance.
The standard definition of normal visual acuity (20/20 or 6/6 vision) is the ability to resolve a spatial pattern separated by a visual angle of one minute of arc.