Color blindness could affect people on
a daily basis without their awareness. Street signs, maps, and
clothes represent just a few of the ways color blindness may impact a
person. One of the only ways to diagnose and treat color blindness is
through a full evaluation at an eye doctor or ophthalmology center.
When you go in for a color blindness
test, there are a variety of tests you may go through. Learn about
some of the tests so you know what to expect and understand some of
the different results.
1. Ishihara Plate Test
One of the more common color blindness
tests is the Ishihara Plate test. This test uses small colored plate
designs typically printed on flashcards. The Ishihara Plate test is
one of the designs more readily available online, but the results
could vary due to screen color calibrations, brightness, and light
impact.
The biggest form of the Ishihara Plate
test will include 38 various plates. Each plate includes a large
collection of dots with a variety of colors. The dots will either
form a number or a line design.
The color palates break down into
different categories to help diagnose color blindness. The categories
include vanishing designs, classification design, hidden digit
designs, and transformation designs. A doctor uses the results to
determine if you struggle to discern certain colors, which may be a
marker of color blindness.
2. Farnsworth Lantern Test
One of the main reasons people test for
color blindness has to do with their careers. A person may seek a
transportation career or art-based career where color recognition is
important. For anything in the transportation field, an eye doctor
will rely on the Farnsworth Lantern Test. A version of this test that
is more commonly used is the Farnsworth D-15.
Originally developed for sailors, the
test focuses specifically on red-green color blindness issues and the
visual impact of various signal lights used on the road or in the
sea. In the test, patients use 15 colored buttons and must place them
in order from 1 to 15 as the colors transition from one hue to the
next.
Once complete, the buttons are flipped
over and numbers are printed on the backside. If the buttons do not
appear in numerical order, the patient may have color blindness
issues. Some versions of the test may include more buttons, different
colored hues, or different light settings.
For example, tests may be done under
yellow light, white light, or the glow of a lantern. The impact of
color blindness could be different with various lighting, so a doctor
will cover multiple bases.
3. CAD Test
A CAD test is a more modern version of
a color blindness test. The test itself acts as a combination of
multiple tests and helps a doctor fully evaluate the color vision of
a patient. The test stands for Color Assessment and Diagnosis and has
been used in several industries for over a decade now.
The test comes in two forms. A
video-based test has a patient identify when a square emerges in a
block of colored tiles. A printed version of the test includes a
variety of slides that feature a wide arrangement of colored squares.
Patients will see squares at some point
in the video test. The sections where people visualize squares, as
well as how long they can see them, help indicate what type of color
blindness a patient may have.
One of the main differences between the
CAD test and the Ishihara Plate Test is the ability to diagnose
blue-yellow color vision issues along with the more common red-green
color blindness problems. Once the test is complete, a doctor
analyzes the results.
To have your color blindness tested,
contact us at the Calvert
Ophthalmology Center. We have a wide range of professional eye
doctors to help diagnose your vision and take any steps needed to
help you adapt to color blindness or to see clearly again.
