Glasses for color blind how do they work? well, I searched this topic and I have found an awesome article in Hebrew which I have decided that I must translate for the English readers.
This article was originally published in Geektime and was written by Shai Zweig, a doctoral student in brain sciences at Bar-Ilan University, Israel, investigates the neural mechanisms behind the color vision.
New glasses solve the problem for color blind people, do they?
In recent years, we have been flooded with news headlines about new wonder glasses that pretend to allow color blind people to see colors just like everyone else.
Glasses For Color Blind How Do They Work?
You’ve probably heard recently about the magic glasses that allow color blind people to see colors they’ve never seen before.
The network was flooded with videos of “the first time,” so, while I was moved by Chris, who for the first time in his life saw the colors of the sunset and wiped a tear in front of John who saw the color of his daughter’s eyes (Hollywood at its best …) it got me wondering, really? Can simple glasses cause color blind people to see colors?
Try not to cry challenge
And if so, how does it work?
But to be fair, let’s say the glasses can help, but the gap between what they really do and titles such as “glasses that turn color blind to color viewers” and a host of dubious statements spoken about in the media is very great.
So what do they really do? Well, for that we’ll have to fill in the following paragraphs with a few explanations, nevertheless, I did not promise that I was going to make your life easy …
So what is a color at all?
Surprisingly, color is not easy to define – you have to work quite a bit to understand what color is and when this understanding sink, it is quite surprising because the color is the brain’s creation, it is directly linked to physical properties but actually, it is kind of illusion.
Confused? So let’s start at the beginning.
Our universe is full of electromagnetic radiation.
This radiation can also be described as a wave, and waves have a feature called wavelength, which is the main feature in which electromagnetic radiation is classified into areas such as radio waves, microwave waves, x-rays, gamma rays, etc.
Well, electromagnetic radiation whose wavelength is in a very narrow range between 380 and 750 nanometers (more or less) is the visible light.
The different colors are connected directly to different wavelengths, with short wavelengths seen by us as purple and blue, the medium lengths are green and yellow and the long ones are orange and red.
A combination of all wavelengths together gives us white light.
Indeed, when white light passes through and breaks (like between air and water, or between air and a prism) it spreads in a way that depends on its wavelengths and then we get the rainbow colors.
Simple no? Color is the way our eye interprets different wavelengths! Well, no, unfortunately here our story begins.
To really understand what is color (and what color blindness is)we must dive into the depths of the eye, where just as in a solar power plant, the light turns into electricity …
The eye is a fairly complex organ that contains several structures when the most important and complex is the retina.
In the retina are the cells which responsible for absorbing the light, converting it into an electrical signal, and after basic processing, it is transferred to the brain.
The first cells in the processing chain of light are light receptors (photoreceptors).
The human eye has four types of receptors such as one responsible for night vision and three others responsible for day vision.
Because at night we are actually color blind, what interests us are the receptors of the day vision.
What separates the three types of receptors responsible for seeing the day is their sensitivity to wavelengths of visible light.
Each of the three is sensitive to different wavelengths.
Their sensitivity to the different wavelengths can be seen in the accompanying diagram.
When the “blue” receptor is particularly sensitive to short wavelengths (purple, blue, etc.), the “green” receptor is sensitive to medium lengths (green and yellow) and the red is sensitive to the long lengths wave (orange and red).
These cells are the only ones that are sensitive to light, so their output is the only signal that indicates the color of the light reaching the eye.
And why am I writing the names of the receptors in quotation marks?
One of the main reasons is that each color receptor in itself is color-blind … Another look at the diagram reveals a very important point: Each receptor is sensitive to a wide range of wavelengths, for example, the red receptor is sensitive to yellow and green light and even slightly blue, it is just a bit more sensitive to green than to orange, so if we illuminate the receptor with a strong green light and in a weak orange light, it will respond in a similar way.
We will try to give an analogy that will help to explain.
Let’s imagine we play darts, I throw a few arrows at the target board and you do not see me throwing the arrows but getting a score report after I’ve finished my arrows.
Let’s say that after I finished throwing the board, I told you that my score is 10, how can you tell if I dropped one drop that hit exactly the center or maybe two drops, one hit the two in the scoring area and the other in the eight and maybe three drops that hit four three and three, etc.
You will probably guess that I did not hit the center exactly but in fact, you lack of information, you only get the result and not the way that I got to it.
In our case, our arrows will be light when the number of arrows symbolizes the light intensity (lots of arrows = stronger light) and the target board will be the color receptor.
Each receptor knows how to report a single number (expressed in electrical voltage), but those who read it can not tell if it is due to a bit of light hitting the target (the wavelength to which the receptor is sensitive) or high-intensity light that misses the target.
That means that a single receptor is color-blind.
What’s going on in our brains?
If so, how does the brain decode the color? The brain takes advantage of the fact that the three types of receptors are differently sensitive to different wavelengths and compares the outputs of the various receptors.
If we continue our analogy, we will add two more target boards whose position will partially overlap the first target board.
Now after my arrows drop you will get three numbers, one for the score on each board, you can compare the numbers and get a better idea of the shots I threw.
In summary, all wavelengths in the light that reaches the eye are decoded into three numbers – the outputs of the various color receptors – and by comparing the three colors the brain creates the illusion of color.
So why an illusion? Now we understand that all that the brain knows is three numbers coming out of the color receptors, so if we can get the receptors to emit the three numbers that represent the color yellow we will think we see yellow while it may very well be that there is not even a bit of “yellow” wavelength in what we see.
Do not believe me? Think about your computer screen, the screens today are based on three red, green and blue light sources (RGB, known from somewhere?).
Each of them knows how to create the appropriate wavelengths, so how can we see yellow on the screen? Well, the screen actually transmits red and green waves but in such a way that makes receptors in our eye to transfer the numbers that correspond to yellow and so our brain is fooled by them and we see yellow …
And what about color blindness?
So after this long explanation, we can say we know what color is, admit you did not think it was so complicated? Now we’ll have a relatively simple explanation of what causes color blindness.
The first thing to say about color blindness is that the phenomenon is actually a generic name for a large number of problems which in all of them, color vision is impaired.
We will focus here on the most common type of color blindness that is “green-red blindness”.
I remember the first time I heard that the most common type of color blindness was the inability to separate red and green, I thought they were joking me.
After all, there are no more distinct colors in my eyes than green and red.
But now that we have a little bit of knowledge about the color mechanism, we can go back to our receptors and understand how about eight percent of men and about one percent of women cannot tell the difference between these two colors.
If we look back at the diagram of the sensitivity of the receptors to the wavelengths, it seems that the sensitivity curve of the green and red receptors is very similar, less than thirty nanometers separate the peaks of these two curves, and this is not by chance … The evolutionary origin of these two receptors is one receptor that splits before About 40 million years ago into two very similar receptors.
Their genetic coding is almost identical and they are located very close to the genetic sequence on the X chromosome.
When there is a problem, and even if it is the smallest one, in one of the genes responsible for coding the receptors, for example on the gene responsible for the green receptor, – One possibility is that the receptor will go out of use, in which case only the second receptor, the red in our case, will remain and the brain will receive instead of three numbers representing a color, only two.
In addition, the overlap between the curve of the blue receptor and that of the red or the green is very small, and so, in fact, the whole area where there is no overlap between the blue receptor curves and the remaining receptor cannot be separated and we will lose the ability to separate red from green since they will be encoded by the same receptor and by only one receptor.
A second possibility is that the damaged receptor will still function but that its curve will “approach” the curve of the second receptor.
So the distance between the peaks will be reduced from thirty nanometers to about five nanometers.
In this case, although we still have three receptors, the numbers produced by the two red and green receptors will be almost identical and will not allow for a good separation between the colors they are “responsible” for – and we have red-green blindness again.
Incidentally, because the receptors are encoded on the X chromosome, men tend to get them much more likely because men have only one copy of this chromosome, and unlike women, they do not have a backup mechanism.
If your mother gave you a defective X chromosome (yes, mom … now you know who to blame), you screw … (although she could very well have an excellent color vision because of the second copy that she holds).
And now for the glasses …
Well, it was long but here we got the glasses … Now that we understand what causes color blindness we can understand how the glasses work and more importantly, who they operate on … The glasses and I rely here on information from the company’s official site, contain filters for filtering different wavelengths.
That is, they reduce the range of wavelengths that reach the eye and they focus mainly on filtering wavelengths in areas between the sensitive peaks of red and green receptors.
And why does it help color blind people? Well, if you are color blind from the first type we presented, which means, one of your receptors is not functioning so they will not help you at all … because no matter what we do, you simply lack the channel to transmit information to the brain, I’m sorry.
The glasses can help those color blindness of the second type, those that still have three channels but the red and green channels are very similar.
In this case, the glasses actually help to make a sharper distinction between different colors and filter out a large part of the wavelengths that can cause confusion between the different colors.
This refinement means that those who are color blind will probably be able to separate now colors that they have not been able to separate in the past – mainly green, orange and red.
Note that this ability always existed in them, just the natural noise in the world confused them.
But do the glasses make them really see these colors? Well, not in the same way that people with normal color vision see them … We can summarize and say that glasses help in a limited way (allow better separation) to give a certain population (green-red color blinders with three types of receptors functioning).
There is a wide range of color blindness (some of which we have not mentioned) that do not fall under this category. So if you are color blind, do not run to buy the glasses before you try them and see that they really help you.
The encouraging news is that most of the red-green blindness (about 75%) are the kind which the glasses have the potential to help.
And what about the rest? Well, do not lose hope, there are some interesting alternatives to glasses.
For example, there is a guy who has no color vision at all and he turns around with a device that translates the world’s color into sounds.
If you ask me it sounds terrible, but hey, he got a lecture at TED because of that so who am I to judge.
A more promising direction, in my opinion, is the direction of genetic treatments.
Today’s technology allows the genome of cells to be engineered using viruses, which can, for example, inject the modified gene of the damaged receptor into the cells and cause them to produce normal receptors.
This method was previously tried in monkeys and was found to be successful.
Glasses for color blind how do they work was written by Shai Zweig, a doctoral student in brain sciences at Bar-Ilan University, Israel, and was translated to English by Eddie for the Disabilitease.com website.