Dyop® - Dynamic Optotype™

Helping the world see clearly, one person at a time




Personal Vision

Infant Vision

Color Screening

Professional Use





How it works




Not everyone sees color in the same way.

Color perception affects your visual skills and personality.



Visual acuity (and accommodation) is regulated by the comparative responses by the cone-shaped Red (L), Green (M), and Blue (S) cone photoreceptors in your eyes.  The cone photoreceptors function as pixelized biological receptors of color much like those of a digital video camera.  The cone photoreceptors also use the focal length disparity between Red and Green to adjust the shape of the lens and bring the overall image into focus (accommodation). 


One of the possible causes of symptoms of dyslexia, migraines, and/or epilepsy is the near vision stress in having a higher ratio of Red to Green photoreceptors (75% red and 20% green photoreceptors).  We call that 75%red/20%green photoreceptor ratio Graphic Vision or “Red-Focused Vision” – (RFV).  That Red-Focused Vision increases the visual stability of distance images but also increases the instability of the lens when it needs to focus on near images.   That RFV visual dissonance at near distances is associated with associated with dyslexia-type symptoms.  Letter-based or Green-Focused Vision – GFV (50% red and 45% green photoreceptors) enables a more stable close visual image.


Graphic implies that you see words as pictographs rather than as letter-based combinations.



Photoreceptor Distribution

Vision / Photoreceptor Type

Red % (L)

Green % (M)

Blue % (S)

Letter-based / Green-Focused Vision (GFV)




Graphic / Red-Focused Vision (RFV)





Letter-based / Green-Focused Vision

Graphic / Red-Focused Vision


Retina Structure

Epithelium  =>  4 Neural Ganglia Layers  =>  Photoreceptors


Retina Color Perception














Wavelengths of light


Dyops® create a unique, and previously unavailable, ability to understand and experiment with visual perception.  We have created a series of experimental Dyop® color/contrast tests whose Red-Focused response by subjects seems to significantly correlate to symptoms of dyslexia, migraines and epilepsy.


Harris – Colored Contacts Paper


Harris – Colored Contacts Poster


Chromatic Modulation Symptoms


Correlation of Reading Speed to L/M Ratios



Download and print the Color Screening Validation Form to record your data.  Your comments, feedback, and test results would be greatly appreciated.  Please send them to Allan@Dyop.org.


There are approximately 100 photoreceptors for every optic nerve fiber.  The retina neural ganglia layers “process” those photoreceptor responses as a biological circuit board with the emphasis on patterns of motion and proximity.  Static photoreceptor stimulation tends to be ignored or increase visual strain.  The difference in the perception of color allows the eye to use those colors to create chromatic triangulation to regulate the focal length of the lens.


Note: Dyop® tests are for vision screening purposes only and are NOT a substitute for an examination by a licensed vision care professional.  The computerized Dyop® tests use Adobe Flash and may be viewed virtually any computer using Google Chrome or Internet Explorer (with ActiveX enabled) or Firefox or Safari or other graphics viewers such as Irfanview with the Flash Graphic plug-ins and the free Adobe Flash Graphic Viewer enabled.  To use the Dyop® tests on a Tablet/SmartPhone, such as an iPad or iPhone, you need to use the Adobe Flash SWIFFY HTML Dyop® test versions, however, the SWIFFY HTML tests will NOT properly display with older versions of Internet Explorer.


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

Copyright©2016 DyopVision™ Associates.  All Rights Reserved.





H.G. Wells had an even better way to see colors.