Editing Ishihara test (section)

==Test procedures==
Being a printed plate, the accuracy of the test depends on using the proper lighting to illuminate the page.  A "daylight" bulb illuminator is required to give the most accurate results, of around 6000–7000&nbsp;K [[color temperature|temperature]] (ideal: 6500&nbsp;K, Color Rendering Index (CRI) >90), and is required for military color vision screening policy. [[Fluorescent bulb]]s are often used in school testing, but the color of fluorescent bulbs and their CRI can vary widely. Fluorescent lighting showed better results and faster recognition speed compared to CFL and LED luminance in trichromats.{{citation needed|date=September 2020}} [[Incandescent bulb]]s should not be used, as their low temperature (yellow-color) gives highly inaccurate results, allowing some color vision deficient persons to pass.

Proper testing technique is to give only three seconds per plate for an answer, and not allow coaching, touching or tracing of the numbers by the subject.  The test is best given in random sequence, if possible, to reduce the effectiveness of prior memorization of the answers by subjects. Some pseudo-isochromatic plate books have the pages in binders, so the plates may be rearranged periodically to give a random order to the test.

Since its creation, the Ishihara Color Blindness Test has become commonly used worldwide because of its easy use and high accuracy. In recent years, the Ishihara test has become available online in addition to its original paper version.<ref>ChallengeTBIshihara{{cite web|url=https://www.challengetb.org/publications/tools/country/Ishihara_Tests.pdf|title=Ishihara Charts|website=www.challengetb.org|publisher=USAID|accessdate=26 October 2023}}</ref> Though both media use the same plates, they require different methods for an accurate diagnosis.