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Related to pseudoisochromatic: Ishihara color test


lack or loss of ability to see (see vision). Legally, blindness is defined as less than 20/200 vision in the better eye with glasses (vision of 20/200 is the ability to see at 20 feet only what the normal eye can see at 200 feet). A person with 20° or less vision (pinhole vision) is also legally blind. In 2002, the number of people classified as legally blind in the United States was estimated at 10 million; millions more had severe visual impairments. The five leading causes of impaired vision and blindness in the United States are age-related macular degeneration, cataract, glaucoma, diabetic retinopathy, and atrophy of the optic nerve. Besides health care problems, issues related to employment, independent living, and literacy should all be considered when caring for patients who are blind. The American Foundation for the Blind is a resource center for information related to visual problems. They can be contacted by calling 1-800-232-5463 or consulting their web site at
blue blindness (blue-yellow blindness) popular names for imperfect perception of blue and yellow tints; see tritanopia and tetartanopia.
color blindness color vision deficiency.
complete color blindness monochromatic vision.
day blindness hemeralopia.
green blindness imperfect perception of green tints; see deuteranopia and protanopia.
legal blindness that defined by law, usually, maximal visual acuity in the better eye after correction of 20/200 with a total diameter of the visual field in that eye of 20°.
night blindness see night blindness.
object blindness (psychic blindness) visual agnosia.
red blindness popular name for protanopia.
red-green blindness (red-green color blindness) popular names for any imperfect perception of red and green tints, including all the most common types of color vision deficiency. See deuteranomaly, deuteranopia, protanomaly, and protanopia.
snow blindness dimness of vision, usually temporary, due to the glare of the sun upon snow.
total color blindness monochromatic vision.
yellow blindness popular name for tritanopia.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.


Apparently of the same color; denoting certain charts containing colored spots mixed with figures printed in confusion colors; used in testing for color vision deficiency.
Farlex Partner Medical Dictionary © Farlex 2012


Apparently of the same color; denoting certain charts containing colored spots mixed with figures printed in confusion colors; used in testing for color vision deficiency.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012
References in periodicals archive ?
Synthetizing, colour simulation tools can be very useful to promote colour universal design and the Simulcheck method can be very useful for knowing if such simulation tools work accurately Until now, the method's main limitation was that it required a colorimeter for measuring the chromatic angle of the pseudoisochromatic stimuli.
Subjects were screened for normal color vision with the Ishihara pseudoisochromatic plate test.[10]
A complete ocular evaluation including Snellen visual acuity testing, Ishihara pseudoisochromatic colour charting, D-15 colour vision charting, slit lamp biomicroscopy, colour fundus photography (Figures 1 & 2) and optical coherence tomography (Figure 3) was done.
Pigment tests based on camouflage patterns composed of confusion colours were developed in Germany in 1876, with the Ishihara pseudoisochromatic test introduced in 1917.
A handheld visual acuity chart and pseudoisochromatic plates were used to test visual acuity and color vision, respectively.
Pseudoisochromatic screening tests aim to identify red-green deficiency and classify protans I and deutans.
Ishihara Pseudoisochromatic test plates were used for these populations while HRR (Hardy, Rand and Ritter) Pseudoisochromatic test plates were used in assessing male population of Lalima village, Terena, India.