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The swinging-flashlight test, also known as the swinging light test, is used in
Bates' guide to physical examination and history taking. 10th ed
Lippincott Williams and Wilkins, New York. p. 244.
The swinging-flashlight test, also known as the swinging light test, is used in medical examination
In a physical examination, medical examination, clinical examination, or medical checkup, a medical practitioner examines a patient for any possible medical signs or symptoms of a Disease, medical condition. It generally consists of a series of ...
s to identify a relative afferent pupillary defect.
Process
For an adequate test, vision must not be entirely lost. In dim room light, the examiner notes the size of the pupils. The patient is asked to gaze into the distance, and the examiner swings the beam of apenlight
A flashlight (American English, US English) or electric torch (Commonwealth English), usually shortened to torch, is a portable hand-held electric lamp. Formerly, the light source typically was a miniature incandescent light bulb, but these h ...
back and forth from one pupil to the other, and observes the size of pupils and reaction in the eye that is lit.
Interpretation
* Normally, each illuminated pupil promptly becomes constricted. The opposite pupil also constricts consensually. * When ocular disease, such ascataract
A cataract is a cloudy area in the lens (anatomy), lens of the eye that leads to a visual impairment, decrease in vision of the eye. Cataracts often develop slowly and can affect one or both eyes. Symptoms may include faded colours, blurry or ...
, impairs vision, the pupils respond normally.
* When the optic nerve is damaged, the sensory (afferent) stimulus sent to the midbrain is reduced. The pupil, responding less vigorously, dilates from its prior constricted state when the light is moved away from the unaffected eye and towards the affected eye. This response is a relative afferent pupillary defect (or Marcus Gunn pupil
A relative afferent pupillary defect (RAPD), also known as a Marcus Gunn pupil (after Robert Marcus Gunn), is a medical sign observed during the swinging-flashlight test whereupon the patient's pupils excessively dilate when a bright light ...
).
See also
*Eye examination
An eye examination, commonly known as an eye test, is a series of tests performed to assess Visual acuity, vision and ability to Focus (optics), focus on and discern objects. It also includes other tests and examinations of the human eye, eyes. ...
References
* Bickley L.S. 2008Bates' guide to physical examination and history taking. 10th ed
Lippincott Williams and Wilkins, New York. p. 244.
External links
{{Physical exam Diagnostic ophthalmology Medical signs Neuro-ophthalmology