Dyop® - Dynamic Optotype™

Helping the world see clearly, one person at a time




Personal Vision

Infant Vision

Color Screening

Professional Use






Experimental Test



Dyop® tests provide Eye Care Professionals with “better patients” and less stress




The Dyop® Professional Visual Acuity/Refraction Test is intended to be a faster and more precise replacement for the Snellen, Sloan, and Landolt tests for determining both visual acuity and refraction end-points.  The simplest method for using the Dyop® test at a virtual 20 foot viewing distance is to utilize a mirror 9 feet in front of the patient displaying Dyop® images which are reflections of the images on a monitor situated 2 feet behind the patient thus creating a virtual 20 foot Viewing Distance.


The Dyop® Professional Visual Acuity Test is calibrated for use on virtually any computer monitor or a 10 inch computer tablet.  The image sizes can also be further adjusted for your specific monitor size. 


The tests are intended to be viewed at a (virtual) viewing distance of 20 feet.  They can be customized to meet the specific needs or actual viewing distance as used by the eye care professional.  The instructions are currently available only in English, but the test image optotypes do NOT require literacy, or even verbal ability, but rather only the ability to indicate the detection of rotation.  (The specific direction of rotation as to clockwise or counter-clockwise is also irrelevant.)


Use the mouse scroll wheel to increase or decrease the Dyop® image angular diameter.  Selecting the smallest Dyop® image detected as rotating will immediately determine acuity.  When the sphere or cylinder lenses are over or under minused, or when the axis vector is misaligned, that non-optimum setting will increase the angular diameter of the smallest detectable rotating Dyop® image.  Dyop® images that are only “twinkling” are NOT rotating. 


On-Line Dyop® Professional Test Users’ Guide

Adobe Acrobat document


The Dyop® Doublet images below are static screen shots of the Experimental Flash version of the test,

and NOT the actual test.


Welcome Screen

Calibration Screen – Viewing Distance and Monitor Size

Click the Dyop® logo to start the test

Initial Dyop® Arc Width 19.2 – Snellen 20/102

Blank the controls with the Space Bar

Dyop® Arc Width 57.2 arc minutes – Snellen 20/702

Dyop® Arc Width 11.3 arc minutes – Snellen 20/40

Dyop® ColorMatrix™ color/contrast options

Red/Green Color Balance

Color Group Screening


Dyop® ColorMatrix


















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.