Videos uploaded by user “Otie Brown”
Changing the eye's power by 2 diopters.
An example of "area of blur", by changing the eye by +/- 2 diopters. Micro blur is detected on the surface of the retina.
Views: 35 Otie Brown
DSO 112 Callibration - the RMS measurement.
I used a RMS volt meter, to confirm the measurement accuracy of the DSO 122 Scope - as demonstrated.
Views: 109 Otie Brown
Optometry analysis/thinking about prevention of myopia.
Dr. Medina, started his kids wearing the plus, while their refractive state was slightly positive, ie, they had 20/20, and wore the plus - to avoid what is certain to happen to kids who start wearing that first minus lens, ar age 6. Success favors a prepared mind, so understanding Brien Holden's prediction for your child's visual future - is critical to understanding why prevention is so critical at age 6, and 20/40 on your home Snellen chart.
Views: 264 Otie Brown
The normal eye's response to a + 3 diopter lens.
The normal eye controls its refractive state - to its average of accommodation plus an offset of 2 diopters. This test is to confirm the refractive change in positive direction.
Views: 78 Otie Brown
Normal eye changes with -3 diopter change in accomm.
All natural eye's control and change their refractive state, to mild changes in their average value of accommodation. This is a sophisticated, dynamic two stage control system. These measurements confirm this bi-direction response to accommodation.
Views: 45 Otie Brown
The importance of accurate statistics for a plus study.
This is an analysis of the results of Dr. Young's plus, or bifocal study. The study was conducted for five years - but the results, after publication, were not taken seriously. This is because the "p" value for each year was not calculated. My re-calculation shows how significant this plus test acyually was - as basic science for the behavior of normal eyes.
Views: 143 Otie Brown
A review of the Ergodic Hypothesis
The video shows the addition of two random signals. Noise is measured as RMS, and peak to peak.
Views: 61 Otie Brown
Video foot note for RMS and Pk - Pk measurements.
This is a foot note for our paper, "A Comparison of Ensemble and Time Series Measurements". This video explains how RMS is stated, and why Pk - Pk is considered to cover 99% of all data points.
Views: 20 Otie Brown
Science and facts for all normal eyes.
While theories can be argued, scientific facts tell the truth. This video shows how the normal eye control it refractive state to its average of accommodation. All normal eyes work this way.
Views: 18 Otie Brown
Why offset is required - for long term control.
Data from the, " control group ", shows that the eye's refractive state is controlled at +2 diopters. Accommodation = -1 diopter ( Reasonable estimate.) "Offset", is applied to the control signal - to maintain +2 diopters, refractive state.
Views: 64 Otie Brown
A Block Diagram of a Position Control System.
This video shows the effect of an un-expected change of 4 diopters in an focal control camera. The Tau of the system is 100 days. The block diagram shows the motor, and the feed back loop with a oscillation. The step-input is applied to the motor, as a voltage impulse.
Views: 39 Otie Brown
The long term response of normal eye.
This is the eye's response to two levels of accommodation: 0.0 diopters and -6 diopters.
Views: 49 Otie Brown
Review of, "Measuring the Eye's Focal Accuracy.
Dr. Peter Greene, evaluated my paper - predicting the tracking accuracy of all eyes - as two control systems. I always appreciate the search for accurate scientific truth - with new ideas and concepts, and necessary reviews.
Views: 53 Otie Brown
Sweet Bo
Our good cat, Bo.
Views: 38 Otie Brown
Theoretical and actual gain in an offset circuit.
The gain of this Op-Amp is 1, because of the use of a resistive divider to create the offset in the output - as demonstrated.
Views: 13 Otie Brown
Errors in a "tracking" control system.
Control systems are very accurate - but not perfect. This video allows calculations of tracking accuracy for the eye's long term control of it refractive state, relative to its average of accommodation. Actual time constants will be discussed in the remarks section of this video. Feel free to add your comments.
Views: 37 Otie Brown
The perturbation response of a control system.
This model shows the eye's response, when the motor has a position distortion of 1.5 diopters - in both directions. The control signal is the accommodatiom level, which is set at 0.0 diopters, for the purpose of this simulation. The eye has a Time-Constant of 100 days, real-time.
Views: 22 Otie Brown
Science, facts, and normal eye proven behavior.
This is the facts and science of all normal eyes. The data is from the control group, and shows refraction being controlled by the average value of accommodation plus an Offset of 2.5 diopters. Plus and mimus lenses, worn for 3 months, show that the eye is a complete control system.
Views: 16 Otie Brown
The eye controls its state - to accommodation.
For tests on all normal primate eyes - this has been objectively proven.
Views: 17 Otie Brown
Why a plus prevention study - is prohibited.
Dr. Young showed that scientific prevention is possible, at 20/40, (-3/4 D self measured ) entering a 4 year college. But success will depend on a person's scientific intelligence - and long term wearing of a plus for all close work. This can never be medicine.
Views: 93 Otie Brown
A Bode graph of an open loop control system.
A motor, is an integrator. An Op-Amp, with feedback, acts as a motor, as shown on this graph. When this system is close-looped, the perfomance, is the same as the normal dymanic eye, with a time-constant of 100 days.
Views: 62 Otie Brown
Adding left and right eye noise to calculate the differential.
This circuit shows that the reverse is also true, for Time-Series noise. If you have the differential RMS, you can calculate the RMS noise of each eye. In this case, the ensemble was 0.213, so each eye has a value of 0.151 RMS, average. These must be time series prediction, based on an ensemble, calculated seperately.
Views: 55 Otie Brown
3)  How the accommodation signal - controls the entire eye.
This is about scientific truth. The dead-band is closer to +/-0.6 Diopters. But watch how close and accurate the eye is - to what you are looking at. These videos are about you understanding that issue. You control your accommodation, and therefore, you control your distant vision - for life.
Views: 55 Otie Brown
Visual input to the accommodation system.
What we look at, is our visual environment - in diopters. The analog, is to convert to volts for the imput to our feedback controlled accommodation system - for accurate simulation.
Views: 17 Otie Brown
Bode Graph of a 100 day Visual Control System.
The normal eye controls it refractive state - to its average of accommodation plus an offset of +2 Diopters. This is a description of how the verticle and horzontal axis are specified.
Views: 27 Otie Brown
The eye's control of its long term refractive state.
This review is to document the design of a servo system, with a time-constant of 100 days.
Views: 35 Otie Brown
A Normal Eye Latching Circuit.
The is an analog model of the normal eye's behavior. When the refraction becomes negative, (20/40) the design tends to latch, making recovery a very slow process. Prevention steps, at 20/40, will prevent this latching.
Views: 29 Otie Brown
Long term behavior of the fundamental eye
This control system duplicates that proven behavior. Tha analog computer leads to a predictave mathematical model - for all normal eyes.
Views: 40 Otie Brown
2)  The effect of Dead-Band on Accommodation.
This presentation shows lens oscillation in the normal eye - when looking at "infinity", or 0.0 Diopters, and then at -3.8 Diopters (10 inches). No person sees this oscillation - although it is always there. It is essential, for continuous accurate focus.
Views: 27 Otie Brown
Electrical simulation of accommodation.
The living eye has an accurate control system, to maintain accurate focus on the fovea. Due to aperture effects, the eye has dead band, and uses hystersis, or continuous motion to gain servo-lock. This simulation shows how this system works - by analysis and a derived equation, for all normal eyes. Enjoy,
Views: 75 Otie Brown
Cute Cat
Views: 59 Otie Brown
The fundamental eye - is a control system.
This physiological model - represents the dynanic behavior, from birth to one year. Data from paper presented.
Views: 42 Otie Brown
Our. Cat
Views: 37 Otie Brown
Camera micro blur detection circuit.
The camera's focus is changed with an adjustable lens. The eye's length is changed by +/- 1.5 Diopters, to show the effect of eye length change, on an in-focus signal.
Views: 37 Otie Brown
Measuring the eye's tracking accuracy.
This concept uses the ergodic hypothesis of statical mechanics, to establish a first estimate of the eye's accuracy in controlling its long term refractive state. Ref: The original peer reviewed paper, for the IEEE / EMBS, is printed below.
Views: 46 Otie Brown
An real-time Stationary Random Process.
I present this concept of a stationary random process, for your understanding of the concept - with no math.
Views: 49 Otie Brown
1)  Dead-Band in The Eye's Accommodation System.
Accommodation is a feed-back system. The eye controls the lens by contious detection of micro blur at the retina. Because of optical dead-band - the lens oscillates - as shown in this video.
Views: 35 Otie Brown
1: Basic Medical Theory, for All Eyes.
This is what is taught in Optometry today. All eyes are defective - besause they have positive and negative refractive states! I disagree, not with the man, but with this failed theory. Let us all be honest about science and the normal eye - as a dynamic system.
Views: 53 Otie Brown