Dyop® - Dynamic Optotype™

Helping the world see clearly, one person at a time




Personal Vision Test

Infant Vision Test

Color Screening Test

Professional Test





Dyslexia Screening




Not everyone sees color in the same way.

Color perception affects your visual skills and personality.


FREE Dyop Color Screening Test


Dyop® Color Screening may be indicative of symptoms of dyslexia, migraines, and epilepsy.


Dyslexia has little to do with (limited) intelligence.  Instead it is typically a symptom of a reduced ability to read letter-based words and an associated difficulty with numbers.  It also seems to be associated with HOW we see colors.


To screen for the color vision group, select the FREE Dyop® Color Screening Test above for use on a PC, iPad, or SmartPhone.  Move away from the identical-diameter spinning Dyop® rings until you CAN ONLY detect either the spinning Green-on-White Dyop® OR the Blue-on-Black Dyop®.  You can also use the Minus (-) symbol to make the spinning rings smaller.  For valid color perception screening, the test should be taken without wearing your glasses or corrective lenses. 


If you can detect only the spinning Green Dyop® you have Letter-Based Vision (LBV).   If you can detect only the spinning Blue Dyop® ring you have Graphic-Based Vision (GBV).  (The High-Red Ratio of Graphic-Based Vision (GBV) enables you to better see pictographic words rather than words as letter-based combinations.)



You may also use the colored animated GIF files on this webpage (below) by moving away from the spinning images and noting, when they are sufficiently smaller, as to whether you CAN ONLY detect spinning of the Green-on-White Dyop® OR the Blue-on-Black Dyop®.   


When you move away from the screen, detecting spinning of ONLY the Blue-on-Black Dyop® is potentially indicative of symptoms of dyslexia, migraines, or epilepsy.


The spinning Dyop® images below are intended for viewing on a PC when the line below is 10 inches long


































The spinning Dyop® color images below are for use on a Smart Phone





















IN THEORY, individuals with chromatic-type dyslexia symptoms have Graphic-Based Vision (GBV) and have an excess ratio of L (red) photoreceptors in their eyes.  The excess of red photoreceptors induces visual dissonance when reading, thus the symptoms associated with being “slow readers.” 


Photoreceptor Response/Distribution

Vision / Photoreceptor Ratio Type

Red % (L)

Green % (M)

Blue % (S)

Letter-Based Vision (LBV)




Graphic-Based Vision (GBV)





Your comments, feedback, and test results would be greatly appreciated.  Please send them to Allan@Dyop.org.

Note: Dyop® tests are for vision screening purposes only and are NOT a substitute for an examination by a licensed vision care professional.  


The Dyop® (Dynamic Optotype™) tests and concept are covered under U.S. Patent US 8,083,353

and International Published Patent WO 2011/022428.

For further information contact: Allan Hytowitz at Allan@Dyop.org

5035 Morton Ferry Circle, Alpharetta, GA, 30022   /   678-893-0580

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