Traditional Snellen chart used for visual acuity testing. Illustration only; this is a scaled image and hence not suitable for vision testing.

Slit lamp examination of the eyes in an ophthalmology clinic

An eye examination is a battery of tests performed by an ophthalmologist or optometrist assessing vision and ability to focus on and discern objects, as well as other tests and examinations pertaining to the eyes. All people should have periodic and thorough eye examinations as part of routine care by the primary care physician, especially since many eye diseases are silent or asymptomatic. Image File history File links This is a lossless scalable vector image. ... Image File history File links This is a lossless scalable vector image. ... Traditional Snellen chart. ... Traditional Snellen chart used for visual acuity testing. ... Image File history File linksMetadata Download high-resolution version (2180x1597, 389 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Ophthalmology Eye examination Slit lamp Metadata This file contains additional information, probably added from the digital camera or... Image File history File linksMetadata Download high-resolution version (2180x1597, 389 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Ophthalmology Eye examination Slit lamp Metadata This file contains additional information, probably added from the digital camera or... Ophthalmology is the branch of medicine which deals with the diseases of the eye and their treatment. ... Optometrists are primary care practitioners for vision and ocular health concerns. ... This does not cite any references or sources. ... An image that is partially in focus, but mostly out of focus in varying degrees. ... A human eye Eyes are organs of vision that detect light. ... The Doctor by Luke Fildes This article is about the term physician, one type of doctor; for other uses of the word doctor see Doctor. ... This is a partial list of human eye diseases and disorders. ... In medicine, a disease is asymptomatic when it is at a stage where the patient does not experience symptoms. ...

Eye examinations may detect potentially treatable blinding eye diseases, ocular manifestations of systemic disease, or signs of tumours or other anomalies of the brain. Blindness is the condition of lacking visual perception due to physiological or psychological factors. ... Tumor (American English) or tumour (British English) originally means swelling, and is sometimes still used with that meaning. ... In animals, the brain or encephalon (Greek for in the head), is the control center of the central nervous system, responsible for behaviour. ...

Comprehensive eye examination

Case history

Entrance tests

• External examination
• Visual acuity
• Amplitude of accommodation
• Color vision
• Cover test
• Stereopsis
• Near point of convergence
• Extraocular motilities
• Pupils
• Visual field screening
• Interpupillary distance

Traditional Snellen chart used for visual acuity testing. ... Amplitude of accommodation (AA) is a measurement of the eye’s ability to focus clearly on objects at near distances (i. ... Color vision is the capacity of an organism or machine to distinguish objects based on the wavelengths (or frequencies) of the light they reflect or emit. ... A cover test is an objective determination of the presence and amount of ocular deviation. ... Stereopsis (from stereo meaning solidity, and opsis meaning vision or sight) is the process in visual perception leading to perception of stereoscopic depth. ... The human eye The pupil is the central transparent area (showing as black). ... The term visual field is sometimes used as a synonym to field of view, though they do not designate the same thing. ...

Refraction

• Lensometry
• Keratometry
• Retinoscopy
• Refraction

• Monocular
• Binocular balance

• Cycloplegic refraction

A keratometer, also known as a 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. ... Retinoscopy is a technique to obtain an objective measurement of the refractive condition of a patients eye. ... Cycloplegia is the paralysis of the ciliary muscle, resulting in a loss of accommodation. ...

Functional tests

• Accommodative system

• Negative relative accommodation
• Positive relative accommodation

• Vergence system

Light from a single point of a distant object and light from a single point of a near object being brought to a focus by changing the curvature of the lens. ... Negative relative accommodation (NRA) is a measure of the maximum ability to relax accommodation while maintaining clear, single binocular vision [1]. See also Amplitude of accommodation Convergence insufficiency Eye examination Positive relative accommodation Category: ... Positive relative accommodation (PRA) is a measure of the maximum ability to stimulate accommodation while maintaining clear, single binocular vision [1]. See also Amplitude of accommodation Eye examination Convergence insufficiency Negative relative accommodation Category: ... A vergence is the simultaneous movement of both eyes in opposite directions to obtain or maintain single binocular vision ^ . The two eyes converge to point to the same object When a creature with binocular vision looks at an object, the eyes must rotate around a vertical axis so that the...

Health assessment

• Slit lamp biomicroscopy
• Direct ophthalmoscopy
• Binocular indirect ophthalmoscopy
• Tonometry
• Amsler grid
• Visual field assessment
• Gonioscopy

The slit-lamp examination looks at structures that are at the front of the eye (the anterior segment): The eyelid, the sclera (white outer structure of the eye), conjunctiva (membranes lining the eyelid and sclera surface), iris (colored part of the eye), natural crystalline lens, and the cornea (thin transparent... Tonometry is the measurement of tension or pressure[1]. A tonometer is an instrument for measuring tension or pressure[2]. In ophthalmology, tonometry is the procedure eye care professionals perform use to determine the intraocular pressure (IOP), the pressure found inside the eye. ... The Amsler Grid, used since 1945, is a black and white grid of horizontal and vertical lines used to monitor a persons central visual field. ... The term visual field is sometimes used as a synonym to field of view, though they do not designate the same thing. ... Gonioscopy describes the use of a goniolens (also known as a gonioscope) in conjunction with a slit lamp or operating microscope to gain a view of the iridocorneal angle, or the anatomical angle formed between the eyes cornea and iris. ...

Advanced techniques

• Corneal topography
• Corneal pachymetry
• Scheimpflug ocular imaging
• Retinal tomography
• Ocular computed tomography
• Scanning laser polarimetry

This article does not cite any references or sources. ...

Setting

Ideally, the eye examination consists of an external examination, followed by specific tests for visual acuity, pupil function, extraocular muscle motility, visual fields, intraocular pressure and ophthalmoscopy through a dilated pupil. Traditional Snellen chart used for visual acuity testing. ... The human eye The pupil is the central transparent area (showing as black). ... The extraocular muscles are the six muscles that control the movements of the eye. ... The term visual field is sometimes used as a synonym to field of view, though they do not designate the same thing. ... Intraocular pressure is the fluid pressure inside the eye. ... In medicine the ophthalmoscope was invented by Hermann von Helmholtz and is an instrument that is used to look into the human eye. ...

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.

Basic examination

Determining a prescription for eyeglasses

Image File history File linksMetadata Download high-resolution version (1296x976, 542 KB)Rig used to determine vision prescription. ... Image File history File linksMetadata Download high-resolution version (1296x976, 542 KB)Rig used to determine vision prescription. ...

External examination

External examination of eyes consists of inspection of the eyelids, surrounding tissues and palpebral fissure. Palpation of the orbital rim may also be desirable, depending on the presenting signs and symptoms. The conjunctiva and sclera can be inspected by having the individual look up, and shining a light while retracting the upper or lower eyelid. The cornea and iris may be similarly inspected. An eyelid is a thin fold of skin and muscle that covers and protects an eye. ... Biological tissue is a group of cells that perform a similar function. ... Fissure (Latin fissura, Plural fissurae) is a groove, natural division, deep furrow, or cleft found in the brain, spinal cord, and liver; or a tear in the anus. ... The conjunctiva is a membrane that covers the sclera (white part of the eye) and lines the inside of the eyelids. ... Schematic diagram of the human eye. ... The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber, providing most of an eyes optical power [1]. Together with the lens, the cornea refracts light and, as a result, helps the eye to focus. ... In anatomy, the iris (plural irises or irides) is the most visible part of the eye of vertebrates, including humans. ...

Visual acuity

Main article: Visual acuity

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. The terms 20/20 and 6/6 are derived from standardized sized objects that can be seen by a "person of normal vision" at the specified distance. For example, if one can see at a distance of 20 ft an object that normally can be seen at 20 ft, then one has 20/20 vision. If one can see at 20 ft what a normal person can see at 40 ft, then one has 20/40 vision. Put another way, suppose you have trouble seeing objects at a distance and you can only see out to 20 ft what a person with normal vision can see out to 200 feet, then you have 20/200 vision. The 6/6 terminology is more commonly used in Europe, and represents distances in meters. Traditional Snellen chart used for visual acuity testing. ...

This is often measured with a Snellen chart. Traditional Snellen chart. ...

Pupil function

Main article: Pupil

An examination of pupilary function includes inspecting the pupils for equal size (1 mm or less of difference may be normal), regular shape, reactivity to light, and direct and consensual accommodation. These steps can be easily remembered with the mnemonic PERRLA (D+C): Pupils Equal and Regular; Reactive to Light and Accommodation (Direct and Consensual). The human eye The pupil is the central transparent area (showing as black). ... Not to be confused with pneumonic. ...

A swinging-flashlight test may also be desirable if neurologic damage is suspected. The swinging-flashlight test is the most useful clinical test available to a general physician for the assessment of optic nerve anomalies. This test detects the afferent pupil defect, also referred to as the Marcus Gunn pupil. In a normal reaction to the swinging-flashlight test, both pupils constrict when one is exposed to light. As the light is being moved from one eye to another, both eyes begin to dilate, but constrict again when light has reached the other eye. This test helps you decide whether reduced vision is due to ocular disease. ... Neurology is a branch of medicine dealing with disorders of the nervous system. ... This article is about the anatomical structure. ... The pupil dilates instead of constricting when the light moves from the good eye to the bad eye. ... The pupil dilates instead of constricting when the light moves from the good eye to the bad eye. ... This article does not cite any references or sources. ...

If there is an efferent defect in the left eye, the left pupil will remain dilated regardless of where the light is shining, while the right pupil will respond normally. If there is an afferent defect in the left eye, both pupils will dilate when the light is shining on the left eye, but both will constrict when it is shining on the right eye. In the nervous system, efferent nerves otherwise known as motor or effector neuron carry nerve impulses away from the central nervous systemto effectors - either muscles or glands. ... The mechanism of the reflex arc In the nervous system, afferent neurons--otherwise known as sensory or receptor neurons--carry nerve impulses from receptors or sense organs toward the central nervous system. ...

If there is a unilateral small pupil with normal reactivity to light, it is unlikely that a neuropathology is present. However, if accompanied by ptosis of the upper eyelid, this may indicate Horner's syndrome. Neuropathology is the study of diseases of the nervous system, and is a medical subspecialty within the specialty of anatomical pathology, itself a division within pathology in many English speaking countries. ... In ophthalmology, ptosis is an abnormally low position (drooping) of the upper eyelid which may grow more or less severe during the day. ... An eyelid is a thin fold of skin and muscle that covers and protects an eye. ... Horners syndrome is a clinical syndrome caused by damage to the sympathetic nervous system. ...

If there is a small, irregular pupil that constricts poorly to light, but normally to accommodation, this is an Argyll Robertson pupil, which is a sign of tertiary syphilis. Light from a single point of a distant object and light from a single point of a near object being brought to a focus by changing the curvature of the lens. ... Argyll Robertson pupils (“AR pupils”) are bilateral small pupils that constrict when the patient focuses on a near object (they “accommodate” with near vision), but do not constrict when exposed to bright light (they do not “react” to light). ... Syphilis is a sexually transmitted disease caused by Treponema pallidum. ...

Ocular motility

Main article: Extraocular muscles

Ocular motility should always be tested, especially when patients complain of double vision or physicians suspect neurologic disease. First, the doctor should visually assess the eyes for deviations that could result from strabismus, extraocular muscle dysfunction, or palsy of the cranial nerves innervating the extraocular muscles. Saccades are assessed by having the patient move his or her eye quickly to a target at the far right, left, top and bottom. This tests for saccadic dysfunction whereupon poor ability of the eyes to "jump" from one place to another may impinge on reading ability and other skills. The extraocular muscles are the six muscles that control the movements of the eye. ... Strabismus (from Greek: στραβισμός strabismos, from στραβίζειν strabizein to squint, from στραβός strabos squinting, squint-eyed[1]) is a condition in which the eyes are not properly aligned with each other. ... Palsy is a medical term derived from the word paralysis that is defined as paralysis of a body part often accompanied by loss of feeling and uncontrolled body movements such as shaking. ... A saccade is a fast movement of an eye, head, or other part of an animals body or of a device. ...

Slow tracking, or "pursuits" are assessed by the 'follow my finger' test, in which the examiner's finger traces an imaginary "double-H", which touches upon the eight fields of gaze. These test the inferior, superior, lateral and medial rectus muscles of the eye, as well as the superior and inferior oblique muscles. The inferior rectus muscle is a muscle in the orbit that depresses, adducts, and rotates the eye laterally. ... The superior rectus muscle is a muscle in the orbit that elevates, adducts, and rotates the eye medially. ... The lateral rectus muscle is a muscle in the orbit that abducts the eyeball (makes it move outwards). ... The medial rectus muscle is a muscle in the orbit that adducts the eyeball (makes it move inwards). ... A top-down view of skeletal muscle Muscle (from Latin musculus little mouse [1]) is contractile tissue of the body and is derived from the mesodermal layer of embryonic germ cells. ... The superior oblique muscle is a muscle in the orbit that causes the eye to look downwards when it is already directed medially (looking towards the nose). ... The inferior oblique muscle is a muscle in the orbit that adducts (medially rotates) and elevates the eyeball. ...

Visual field (confrontation) testing

Main article: Visual field

Main article: Visual field test

Evaluation of the visual fields should never be omitted from the basic eye examination. Testing the visual fields consists of confrontation field testing in which each eye is tested separately to assess the extent of the peripheral field. To perform the test, the individual occludes one eye while fixated on the examiner's eye with the non-occluded eye. The patient is then asked to count the number of fingers that are briefly flashed in each of the four quadrants. This method is preferred to the wiggly finger test that was historically used because it represents a rapid and efficient way of answering the same question: is the peripheral visual field affected? The term visual field is sometimes used as a synonym to field of view, though they do not designate the same thing. ... A visual field test is an examination that may be performed to analyze a patients visual field. ...

Common problems of the visual field include scotoma (area of reduced vision), hemianopia (half of visual field lost), homonymous quadrantanopia (involving both eyes) and bitemporal hemianopia. The word scotoma is derived from the Greek word for darkness. ... Hemianopsia is the loss of half the vision in both eyes. ... Bitemporal hemianopia is a specific type of visual disturbance in which sight in the outer half of the visual field of each eye is lost. ...

Intraocular pressure

Intraocular pressure can be measured by any of a series of devices designed to measure the outflow (and resistance to outflow) of the aqueous humour from the eye. The aqueous humour is a a thick watery substance that is located in the eye. ...

Ophthalmoscopy

Ophthalmoscopic examination may include visually magnified inspection of the internal eye structures and also assessment of the quality of the eye's red reflex.

Ophthalmoscopy allows the one to look directly at the retina and other tissue at the back of the eye. This is best done after the pupil has been dilated with eye drops. A limited view can be obtained through an undilated pupil, in which case best results are obtained with the room darkened and the patient looking towards the far corner. Human eye cross-sectional view. ...

The appearance of the optic disc and retinal vasculature are the main focus of examination during ophthalmoscopy. Anomalies in the appearance of these internal ocular structures may indicate eye disease or condition. The optic disc or optic nerve head is the location where ganglion cell axons exit the eye to form the optic nerve. ...

A red reflex can be seen when looking at a patient's pupil through a direct ophthalmoscope. This part of the examination is done from a distance of about 50 cm and is usually symmetrical between the two eyes. An opacity may indicate a cataract. The red reflex refers to the reddish-orange reflection from the eyes retina that is observed when using an ophthalmoscope or retinoscope. ... The ophthalmoscope, invented by Hermann von Helmholtz, is an instrument used to examine the eye. ...

Slit-lamp

Close inspection of the anterior eye structures and ocular adnexa are often done with a slit lamp machine. A small beam of light that can be varied in width, height, incident angle, orientation and colour, is passed over the eye. Often, this light beam is narrowed into a vertical "slit", during slit-lamp examination. The examiner views the illuminated ocular structures, through an optical system that magnifies the image of the eye. The slit-lamp examination looks at structures that are at the front of the eye (the anterior segment): The eyelid, the sclera (white outer structure of the eye), conjunctiva (membranes lining the eyelid and sclera surface), iris (colored part of the eye), natural crystalline lens, and the cornea (thin transparent...

This allows inspection of all the ocular media, from cornea to vitreous, plus magnified view of eyelids, and other external ocular related structures. Fluorescein staining before slit lamp examination may reveal corneal abrasions or herpes simplex infection. Fluorescein in dropper used for eye examination. ... For corneal abrasions in dogs and cats, see corneal ulcer. ... This article is about the disease. ...

The binocular slit-lamp examination provides stereoscopic magnified view of the eye structures in striking detail, enabling exact anatomical diagnoses to be made for a variety of eye conditions.

Also ophthalmoscopy and gonioscopy examinations can also be performed through the slit lamp when combined with special lenses. These lenses include the Goldmann 3-mirror lens, gonioscopy single-mirror/ Zeiss 4-mirror lens for (ocular) anterior chamber angle structures and +90D lens, +78D lens, +66D lens & Hruby (-56D) lens, the examination of retinal structures is accomplished. In medicine the ophthalmoscope was invented by Hermann von Helmholtz and is an instrument that is used to look into the human eye. ... Gonioscopy describes the use of a goniolens (also known as a gonioscope) in conjunction with a slit lamp or operating microscope to gain a view of the iridocorneal angle, or the anatomical angle formed between the eyes cornea and iris. ...

References

• eMedicine article on Neuro-ophthalmic examination

See also

Conditions diagnosed during eye examinations

Main article: List of eye diseases and disorders

• Amblyopia
• Diplopia
• Myopia
• Hyperopia
• Presbyopia
• Strabismus

This is a partial list of human eye diseases and disorders. ... Amblyopia, or lazy eye, is a disorder of the eye. ... Diplopia, commonly known as double vision, is the perception of two images from a single object. ... Normal vision. ... Hyperopia, also known as hypermetropia or colloquially as farsightedness or longsightedness, is a defect of vision caused by an imperfection in the eye (often when the eyeball is too short or when the lens cannot become round enough), causing inability to focus on near objects, and in extreme cases causing... Presbyopia (Greek word presbyteros (πρεσβύτερος), meaning elder) is the eyes diminished ability to focus that occurs with aging. ... Strabismus (from Greek: στραβισμός strabismos, from στραβίζειν strabizein to squint, from στραβός strabos squinting, squint-eyed[1]) is a condition in which the eyes are not properly aligned with each other. ...

Other tests that may be performed during eye examinations

• Electrooculography
• Electroretinography

Electrooculography (EOG) is a medical technique for measuring the resting potential of the retina, the resulting signal is called electrooculogram. ... Electroretinography, is used to measure the electrical responses of various cell types in the retina, including the light-sensitive cells (rods and cones) and the ganglion cells. ...

Miscellaneous

• Binocular vision
• Eyeglass prescription
• Orthoptics
• Stereopsis
• Vergence

Binocular vision is vision in which both eyes are used synchronously to produce a single image. ... Using a phoropter to determine a prescription for eyeglasses An eyeglass prescription is a written order by an ophthalmologist or an optometrist to an optician for eyeglasses. ... Orthoptics (from the Greek words ortho meaning straight, and optikas meaning vision [1]) is the discipline dealing with the diagnosis and treatment of defective eye coordination, binocular vision, and functional amblyopia by non-pharmaceutical and non-surgical methods, e. ... Stereopsis (from stereo meaning solidity, and opsis meaning vision or sight) is the process in visual perception leading to perception of stereoscopic depth. ... A vergence is the simultaneous movement of both eyes in opposite directions to obtain or maintain single binocular vision ^ . The two eyes converge to point to the same object When a creature with binocular vision looks at an object, the eyes must rotate around a vertical axis so that the...

External Links

• Eye examination equipment in the market
• Hollands of London Eye test information
• What A Vision Test Involves?