Thread: Infra-Red Human Vision

I was just doing some revision on the eye for my biology exam and I was thinking it might actually be possible to make a human see in infra-red spectrum.

From my knowledge we have three types of cone cells, each with a type of a pigment called opsin in the rhodopsin in that cell. The cone cells allow us to see red/green/blue (colour vision) so if the three different types of opsin can be isolated in a lab and the factors in the DNA (or whatever controls the differences) can be obtained and manipulated then couldn't we be able 2 make the opsin react to the infra-red spectrum or any spectrum of electromagnetic radation? therefore allowing the cone cells to see not only visible light but a whole new range.

The trouble is how to grow the cells on the retina (fovea) of an animal without damaging the eye?

What would it be like looking at infra-red and visble light at the same time? You can visibly see a wall but then you have got a slight red glow of a person behind that wall? I just think it would be so weird, and yet so interesting, but the possibility of creating a race that would think they are more dominant to the rest of us just because they can see more?

Basically, we don't know if it's possible or not. We would have to completely understand the structure of opsin and exactly how it's structure enables it to react to light, which I'm pretty sure is something we do not yet know. Even then, extrapolating that knowledge into reaction to a whole different wavelength of light with no prior reference would be very challenging, if possible. I'm not saying it isn't - we just don't know yet.

If you want to know what it's like to see infrared, get your hands on a camera or webcam, and take it apart (or have a technologically savvy friend do it) and remove the infrared filter. Put it back together again, and you have a device that now sees into the infrared spectrum. My boyfriend did that to a camera of his, and it was pretty fun. You can even see through some materials that allow infrared light to pass but not visible light. The ends of tv remotes look like flashlights when their buttons are pressed. =p

Originally Posted by JasonRShane

I was thinking it might actually be possible to make a human see in infra-red spectrum.

From my knowledge we have three types of cone cells, each with a type of a pigment called opsin in the rhodopsin in that cell. The cone cells allow us to see red/green/blue (colour vision) so if the three different types of opsin can be isolated in a lab and the factors in the DNA (or whatever controls the differences) can be obtained and manipulated then couldn't we be able 2 make the opsin react to the infra-red spectrum or any spectrum of electromagnetic radation? therefore allowing the cone cells to see not only visible light but a whole new range.

The trouble is how to grow the cells on the retina (fovea) of an animal without damaging the eye?

Let me get you up with the teminology so we're talking about the same thing:

Rhodopsin refers specifically to the photopigment of the rod cells. Rod cells are monchromatic, so you don't see anything but a bluish color with them. If you're talking about altering your color vision, you need to look at photopsins. Like you said, there's three photopsins: erythrolabe, chlorolabe, and cyanolabe, each is responsible for a particular wavelength of light which equates to red, green and blue vision. The thing that enables the difference in color discrimination, is that there are key amino acid residues within the color proteins that interact with the molecule (retinal), inside the protein. To those who don't understand molecular biology, here's an analogy:

Think of the protein part of photopsins as a bird cage and retinal as the bird in that cage. There are three different birds, each in separate cages, that react to different colors of light. When the bird sees it's color, it flaps its wings (reacts) in response to that color. The thing you need to change, to change your color discrimination, is the bird or the light it can see.

The way some insects see ultraviolet light, is to have an oil droplet at the front of the photoreceptor. This essentailly filters the light to a wavelength that can be detected by the photoreceptor. This would be like having one of the birds wear glasses that makes light that they wouldn't normally see, visible. This way they are indirectly receptive to otherwise invisible light. You might be able to devise a similar mechanism for human photoreceptor cells.

I think the most likely way you're going to do it is through transgenic experiments or to implant photovoltaic cells, receptive to your wavelength of interest, into the retina and wire them to optic neurons. Until then, goggles will have to do.

Interesting thought, thanks for the brain food.

well you certainly know your eyes :wink:

Well, I spend a lot of time studying them.

or you could just implant a fake eye which has a processer and stuff and connect it to the ON

You should also take into account that retinal probably has limits on how much the wavelength can be in the infrared before it stops responding. The trick is that the molecule reacts with a conformational change (change of shape) to light of a given wavelength change. Lower wavelengths may not be able to cause the conformational change. Ultraviolet light doesn't cause such problems as you can always transform too short a wavelength into something more acceptable, but if the wavelength is too long it is difficult to do something about it.

Following the above metaphor, giving the cage red, gree or blue filter from the direction of the light source will cause the bird to react only to that color of light. with ultraviolet light you can use a fluorescent coating on a filter (just like in fluorescent lights). No fluorescence will however enhance infrared light to visible light, as far as I know only electronics can do that.

Thus to make this work you would possibly have to change retinal into something else that works with IR and as a consequence likely the opsine into something that works with the retinal replacement.

Originally Posted by TaO!

The way some insects see ultraviolet light, is to have an oil droplet at the front of the photoreceptor. This essentailly filters the light to a wavelength that can be detected by the photoreceptor. This would be like having one of the birds wear glasses that makes light that they wouldn't normally see, visible. This way they are indirectly receptive to otherwise invisible light. You might be able to devise a similar mechanism for human photoreceptor cells.

I think the most likely way you're going to do it is through transgenic experiments or to implant photovoltaic cells, receptive to your wavelength of interest, into the retina and wire them to optic neurons. Until then, goggles will have to do.

Interesting thought, thanks for the brain food.

What about (theoritcally) having some sort of retractable lens or cornea that filters in the infra-red. Maybe use some nanotech, or something, to create it. :?

Originally Posted by DaBOB

What about (theoritcally) having some sort of retractable lens or cornea that filters in the infra-red. Maybe use some nanotech, or something, to create it. :?

Such a thing would not work with the photosensitive pigments in our eyes. Maybe a change in an opsin would do the trick, but probably it's retinal that wouldn't get enough energy from the weaker infrared photon to change its geometry, which is necessary for it to cause a signal. An infrared photon is a lot less energetic than a VIS photon. Maybe a light trap could do the trick adding multiple photons, as is done in chlorophyll (i think).
UV light on the other hand is simple (relatively), you would simply have to cover the retina with a fluorescent film and then filter all the other light.

Doesn't the brain also need to be "configured" to be able to process anything else that is not on the visible spectrum? If you take radiation that we associate with "green", the green actually doesn't exist, its just a property given to it by the brain so that we can distinguish it from other wavelengths. Photo receptors that is responsive to UV or Infra-red shouldn't be a problem as there are species that have eyes that can detect radiation, like pit-vipers. UV would be much easier no doubt.

As for the UV, the re is no problem as the fluorescence would "convert" the UV into some color of VIS. Anything goes, it can be green, red, with a combination even white.
The new pigment would not cause a new signal, you'd have to make a whole new photosensitive cell for that and probably even change the neuronal wiring of the eye and/or the optic centers. Otherwise you would just replace/extend one of the existing colors.
I think however that whatever your solution, the adaptation of the brain would be the least of your problems. I have heard of experiments where the picture was turned around using special glasses and after some time the subject (human) didn't even note the difference (unless he took the glasses of). I therefore doubt that changing the nature of one color and maybe even adding a fourth one will prove to be a challenge for our brain.

i want infrared vision!! ... and laser beams that come out my eyes like superman :P (i think superman has laser beams lol)

I think you should investigate vision in cats.

Have you ever noticed how a cat will walk into a room and head straight for the warmest spot? I'm sure they have infra-red vision...

cat's don't have infrared vision however there vision is much more accute on our own, perhapse they can detect just the slightest amount of heat-haze with their super vision to determine that is the warmest spot

I think it would be far easier to put an implant in either your eye or your brain and have the infra-red (or UV) image converted into a false color one, this way you wouldn't have to deal with perceptual issues. That's the system we currently use, except the tools are all external.

The animals and insects that have eyes that detect UV or infra-red radiation can also "perceive" it in their brains, while ours does not seem to be able to.

Originally Posted by n300

Originally Posted by DaBOB

What about (theoritcally) having some sort of retractable lens or cornea that filters in the infra-red. Maybe use some nanotech, or something, to create it. :?

Such a thing would not work with the photosensitive pigments in our eyes. Maybe a change in an opsin would do the trick, but probably it's retinal that wouldn't get enough energy from the weaker infrared photon to change its geometry, which is necessary for it to cause a signal. An infrared photon is a lot less energetic than a VIS photon. Maybe a light trap could do the trick adding multiple photons, as is done in chlorophyll (i think).
UV light on the other hand is simple (relatively), you would simply have to cover the retina with a fluorescent film and then filter all the other light.

I mean, if the lens could somehow convert the wavelength of the photons so that what is once infra-red is now in our visible spectrom. Just like a machine would do: detects the heat and displays it to use on colors we understand.

Such a lens would have to achieve two things at the same time that are both somewhere between extremely complicated and simply impossible with todays technology.
#1 Make an amplifier for light of some sort (today it is done via sensors and screens).
#2 Amplify the light rays without changing their direction, that means recreating the VIS ray directed the same as the IR ray was, or the retina would not get the picture focused.

Such a lens would also need an external source of energy as the lower energy IR rays would when transformed into the same amount of energy in VIS photons (somehow) give a lot less VIS photons (10% and likely less, not counting the energy loss in the process).

You could solve the problem #2 with either moving the "lens" farther apart from the eye (like in VR goggles) or by making the light amplifying film on the retina thus amplifying an already sharp image. #1 is quite the stuff of dreams, though not impossible in principle I think. I would however consider an external sensor connected with the brain better (more robust, easier to control, replace, upgrade, CHEAPER)

after all, we all can be supermen with super vision.

after reading this thread i got a fictionous idea. it'll be great if we can develop a gadget which enable us to change the charge of protein molecules in photo receptor cells so their reaction range will differ, so hopefully they will be stimulated by different spectrum of photons.

We might change the charge by changing the PH of the cell. But that's hard as the cell membrane is very much freely permeable to H+.

So after we find how to do that, we'll be able to tune our spectrum like we do in a television.

finally we can have some somatic neural connection to that tuning device and ultimately be supermen.

hehe

thanks