Dyop® - Dynamic Optotype™

Helping the world see clearly, one person at a time




Personal Vision

Infant Vision

Color Screening

Professional Use


How it works

Using the Test

Visual Impairment

How it works

Using the Test



Adobe Flash Graphics format


Note: The Dyop™ vision tests are for screening purposes only and are NOT a substitute for an examination by a licensed vision care professional.  All of the Dyop™ Vision Tests are in an Adobe Flash Graphic format and may be viewed using Internet Explorer (with ActiveX enabled) or Google Chrome or Firefox or Safari or other graphic viewers such as Irfanview with the Flash Graphic plug-ins or using the free Adobe Flash Graphic Viewer enabled.  Because they use FLASH, the Dyop™ tests will NOT yet work on an iPad or iPhone.  Because they use FLASH, the Dyop™ tests will NOT work on an iPad or iPhone unless you use the Photon Browser


This is EXPERIMENTAL test.


Reading is an adaptive cultural learned human process that dates back only about 3500 years and was NOT part of the previous 3 million years of human development.  As a result, some people have difficulty maintaining convergence and the close focus necessary for extended periods of reading without suffering significant visual stress.  The ability to maintain that convergence for long periods of time is essential for some careers such as the humanities and law where extensive reading is required.  It might also be a significant factor in determining who can or cannot successfully adjust to wearing progressive glasses. 




Traditional visual stress tests using text material typically take at least 15 to 30 minutes to produce symptoms of visual stress.  It is hoped that the Dyop™ Convergence Test will provide a quick and precise method for convergence and stress determination.


This EXPERIMENTAL test is designed to measure vergence, accommodation, and visual stress by determining how long an individual can maintain convergence (looking “cross-eyed) with two Dyop™ images to create the illusion of a third single central Dyop™ image. 


To use the Dyop™ Convergence Stress Test: open the test (using the link above), select the proper monitor size and sit 5 feet from your monitor.  Converge the two Dyop™ images (looking "cross-eyed") so that you see a third central Dyop™ image.  Click Start to begin the test and note as the central image incrementally reduces in diameter.  Try to maintain that central single Dyop™ image for five minutes or more (or as long as possible).  Note the length of time when that converged image can no longer be maintained.  Subjects with a tendency for visual stress will likely have trouble maintaining the single central image for more than two minutes.


For a further discussion of the peripheral distortion associated with progressive lenses go to www.InducedDyslexia.com


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©2013 DyopVision™ Associates.  All Rights Reserved.