Dyop® - Dynamic Optotype™

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How it works

 

 

 

 

 

 

 

Dyop® motion detection is the "revolutionary" method of measuring vision

 

 

 

 

 

 

 

   Dyop Strobic Stimulus

 

 

 

Dyop® (short for dynamic optotype) is segmented, circular visual target whose gaps and segments rotate at a constant velocity to create a strobic stimulus of the eyes’ photoreceptors.  That gap/segment stimulus is used to measure visual clarity and determine refractions. The smallest Dyop diameter detected as moving creates an acuity and refraction endpoint.

 

The eye developed to respond to light, then colors, then shapes, and then distances.  In the process of learning to respond to shapes and distances it learned to respond to motion as a function of those shapes.  

 

The bioelectrical responses of the photoreceptors function much as the pixels in a computerized (electronic).  Your brain uses the response of about 100 photoreceptors for every optic nerve going to the brain to create vision and to bring that image into focus.  The photoreceptors not only allow you to see in color (primarily red, green, and blue for most people), but the refresh rate of the photoreceptors allows you to track changes in the location of those images.  The comparative focal depth of the red, green, and blue stimulus of those images regulates the shape of the lens and the focal clarity.

 

However, we normally aren’t aware of that photoreceptor strobic stimulus, as facilitated by the saccade process, because it would interfere with being able to see the lines and shapes as transmitted to the brain.  We literally would "see the trees rather than the forest."  The cognition effect is the same as if you got close enough to see the pixels on your monitor.  You totally lose the ability to see the shapes and understand the words.  It is also why fixating on a shape will literally have that shape seem to disappear as the photoreceptors lose their ability to bio-electronically respond.

 

When the moving gap/segment area of a Dyop gets too small, that stimulus is too small for the photoreceptor pixel effect to be detected by the eye.  The smallest Dyop stimulus area detected as moving (0.54 arc minutes squared, or about 20 photoreceptors) creates an acuity and refraction endpoint.

 

 

Light passes through the lens

to reach the retina

Retina Structure

Epithelium  =>  4 Neural Layers  =>  Photoreceptors

 

Photoreceptors as Pixels

 

Retina Color Perception

Wavelengths of light

 

 

 

 

 

 

 

 

Light => => => Perception

 

 

Faster and more accurate visual acuity testing

 

With the 1862 Snellen test, and other static image charts which derived from it, the target letters get increasingly blurry as they get smaller.  Cognition based letters become a guessing game for both the doctor and patient requiring conceptual processing by the patient as much as it does visual clarity. 

 

For Dyop testing, as the Dyop diameter (angular width) and the gap/segments gets sufficiently smaller, the strobic stimulus on the photoreceptors is no longer sufficiently large enough for the motion of the gap/segments to be detected. The smallest Dyop diameter (arc width) detected as moving/rotating indicates the visual acuity and refraction endpoint. The direction of rotation is irrelevant.   When a patient is presented with 2 Dyops, side by side, one moving and one static, and is asked to determine which of the two Dyops is spinning (Left or Right), the smallest Dyop diameter detected as moving/rotating is that acuity endpoint.

 

The added precision and reliance upon a Dyop physiological visual response, rather than cognition of European-type letters, provides a more precise, consistent, accurate, and efficient method for measuring visual acuity. It also lets the Dyop test be used for people with limited literacy and very young children.

 

The History of Vision Measurement

 

Hundreds of thousands of years ago our eyes developed as survival tools to spot predators and game.  Thousands of years ago, visual clarity (acuity) was defined by the ability to see the nighttime gap between two of the smaller stars in the handle of the Big Dipper constellation.

 

 

Stellar Acuity

Static Letter-based Acuity

Dyop Strobic Stimulus Acuity

 

In 1862 Snellen defined visual acuity as the ability to identify letters, since reading had become a dominant social skill.  European vision science used the convenience of black letters on a white background as the acuity benchmark, although much of what we see is NOT in black and white.  Also, only a small portion of the earth’s population could read European letters, and that letter-based response was, and is, frequently inconsistent and imprecise.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

20/22

 

20/20

 

20/18

 

1862 Snellen Vision Testing

 

21st Century Dyop® Vision Testing

 

The strobic Dyop stimulus lets you sense the pixel response to the images you are seeing.

 

Twenty first century technology is letter-based technology.  Today’s visual acuity is primarily measured by the clarity and ability to read text on an electronic display.  Unfortunately, vision science has not kept up with the precision and demands of 21st century visual needs.

 

 

 

 

 

 

 

 

 

 

The more precisely calibrated Dyop® tests are intended as a global replacement for Snellen, Sloan, and Landolt optotypes.

 

The personal version of the Dyop® test is intended to measure your visual clarity; however getting glasses or contact lenses requires a refraction performed by your eye doctor which CANNOT be done on a two-dimensional display such as a computer.  Measure your vision with the Dyop test using the Dyop Personal Acuity Test, and if you can’t see clearly enough, GO SEE YOUR EYE DOCTOR.

 

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

 

 

“Any sufficiently advanced technology is indistinguishable from magic.”
- Arthur C. Clarke’s Third Law

 

As a culture we are only as good as our memory.  As a species we are only as good as our vision.

 

Just as the hand, held before the eye, can hide the tallest mountain, so the routine of everyday life can keep us from seeing the vast radiance and the secret wonders that fill the earth.

-          Chasidic, 18th Century

 

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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