[Spamname x100921 (OP)]

Can some one explain why i can see infrared, and i can hear ultrasonic?
So i first notice from looking at infrared remote, and i just can see it when clicking the button there is red light, and in   internet or teacher and friend said you cant see infrared. So what happen with my sight?
And i can hear ultrasonic too which normally human cant hear, i notice when someone using mouse repelent, and i can hear it goodly and it makes my hearing hurt so bad! So what happen with my hearing?

[Bored chemist]

The definition of "infra red" is a bit loose.
I can, just about, in a dark room see the glow from a TV remote.

And some people, especially if they are young and haven't spent too much time listening to loud music can hear sounds that are normally considered "ultrasonic".

You can probably find an app on line which acts as signal generator - that might give you some idea of how high pitched a sound you can hear.

[evan_au]

Many people can see an infra-red transmitter - with the help of their smartphone.
- One of the cameras on my smartphone does not have an infra-red filter.
- Put the camera in video mode (as if you were lining up a photo), and have someone point the infra-red remote at the camera. You can see a flashing light at the end of the remote control.
- You may need to switch your camera to "selfie" view to see it.

[Spamname x100921 (OP)]

me people, especially if they are young and haven't spent too much time listening to loud music can hear sounds that are normally considered "ultrasonic".

Bright or dark room i can see the infra red.
Am a gamer, music listener, movie watcher. so i listen a lot of sound, and very loud when gaming.

[Spamname x100921 (OP)]

young

Naked eye! i tell some one to look it up too, bet they said see nothing.
Am not trying to proof anything, i just want to know why?

[evan_au]

Naked eye! ... i just want to know why?

The human eye has 3 color-sensing cones: roughly red, green and blue (some color-blind people can see only 2 colors directly).

But within these, there is genetic variation - there are two common variants of the red gene that have different spectral responses, allowing some women to see 4 colors directly.

It is possible that you have a genetic variant that has slightly better response into the longer wavelengths, or near-infra-red.
- These infra-red photons carry low energy, so it is hard for infra-red photons to activate chemical pathways
- Without these sensitive pathways being activated all the time by normal body temperature...

You could test this by getting a prism to split light into a rainbow.
- Get another person to mark on a piece of paper the limits of visible light they can see, from red to violet.
- Then you mark the paper with the colors you can see, from red to violet
- See how much they overlap. The Sun produces quite a lot of light at infra-red, and glass is somewhat transparent to near-infra-red.
- For a better test, use a diffraction grating, but they tend to be harder to obtain than a prism.

See: https://en.wikipedia.org/wiki/Tetrachromacy#Humans

[Eternal Student]

Hi.

   Seeing infrared is unusual.  We might expect a little variation among human beings for most things we can sense that involve some mechanical process of detection.  For example, hearing sounds into the ultrasonic range.
   It's a little bit stranger for eye sight because a lot of it boils down the ability of a particular molecule to absorb a photon.  This is not a mechanical process.  If you had some genetic variation that made your photosensitive molecules different to most other people, this would probably make you blind to certain colours.  It's likely that even a small change in those pigments would stop them from working at all, rather than making them favour slightly longer wavelenegths.

    I found this article on the internet:  https://www.sciencedaily.com/releases/2014/12/141201161116.htm
I don't know how reliable it is.   Their findings were apparently published in the "Proceedings of the National Academy of Sciences (PNAS)".
   It suggests that, in some cases, the standard pigments in the retian can absorb two low frequency photons in short succession and this can trigger the usual chemical changes in the pigment and cause a signal to be sent along the optic nerve.  This usually requires the infrared source to be "pulsed" (rapidly turned on and off) which might be exactly what your IR remote control is doing.  Anyway, they used a laser which produced IR radiation and this is what they said:
    .... packing a lot of photons in a short pulse of the rapidly pulsing laser light makes it possible for two photons to be absorbed at one time by a single photopigment, and the combined energy of the two light particles is enough to activate the pigment and allow the eye to see what normally is invisible.

   It could be that your eyes (the lens, the cornea, the vitreous humor etc.) don't absorb or filter out as much IR radiation as most other people.  So other people don't generally experience two IR photons hitting the photopigments in the retina in rapid succession  -  but you do.

Best Wishes.

[Spamname x100921 (OP)]

Naked eye! ... i just want to know why?

The human eye has 3 color-sensing cones: roughly red, green and blue (some color-blind people can see only 2 colors directly).

But within these, there is genetic variation - there are two common variants of the red gene that have different spectral responses, allowing some women to see 4 colors directly.

It is possible that you have a genetic variant that has slightly better response into the longer wavelengths, or near-infra-red.
- These infra-red photons carry low energy, so it is hard for infra-red photons to activate chemical pathways
- Without these sensitive pathways being activated all the time by normal body temperature...

You could test this by getting a prism to split light into a rainbow.
- Get another person to mark on a piece of paper the limits of visible light they can see, from red to violet.
- Then you mark the paper with the colors you can see, from red to violet
- See how much they overlap. The Sun produces quite a lot of light at infra-red, and glass is somewhat transparent to near-infra-red.
- For a better test, use a diffraction grating, but they tend to be harder to obtain than a prism.

I willl learn more then and see about the prism u said, thanks for the logical answer, btw am a man.

[Spamname x100921 (OP)]

Hi.

   Seeing infrared is unusual.  We might expect a little variation among human beings for most things we can sense that involve some mechanical process of detection.  For example, hearing sounds into the ultrasonic range.
   It's a little bit stranger for eye sight because a lot of it boils down the ability of a particular molecule to absorb a photon.  This is not a mechanical process.  If you had some genetic variation that made your photosensitive molecules different to most other people, this would probably make you blind to certain colours.  It's likely that even a small change in those pigments would stop them from working at all, rather than making them favour slightly longer wavelenegths.

    I found this article on the internet:  XXXXXXXXXXXXXX
I don't know how reliable it is.   Their findings were apparently published in the "Proceedings of the National Academy of Sciences (PNAS)".
   It suggests that, in some cases, the standard pigments in the retian can absorb two low frequency photons in short succession and this can trigger the usual chemical changes in the pigment and cause a signal to be sent along the optic nerve.  This usually requires the infrared source to be "pulsed" (rapidly turned on and off) which might be exactly what your IR remote control is doing.  Anyway, they used a laser which produced IR radiation and this is what they said:
    .... packing a lot of photons in a short pulse of the rapidly pulsing laser light makes it possible for two photons to be absorbed at one time by a single photopigment, and the combined energy of the two light particles is enough to activate the pigment and allow the eye to see what normally is invisible.

   It could be that your eyes (the lens, the cornea, the vitreous humor etc.) don't absorb or filter out as much IR radiation as most other people.  So other people don't generally experience two IR photons hitting the photopigments in the retina in rapid succession  -  but you do.

Best Wishes.

Thanks for answering, ill learn more from the words u said, then i will understand your explanation. And I am not a color blind person, i have been checked by the doctor!

[alancalverd]

Infrared and ultrasonic are defined as beyond the range of vision or hearing, respectively. So if you can see or hear them, they aren't IR or US. Might be interesting to determine the exact wavelengths you can sense, which may indeed lie outside the normal range and could be scientifically interesting. 


On the flip side I knew of people who couldn't follow rapid motion. Turned out they had lost most of their retinal rods but had spontaneously recovered from HIV without treatment. The human body remains a bit of a mystery!

[evan_au]

some women to see 4 colors directly...btw am a man..And I am not a color blind person

That means that you have genes for the standard 3 colors.

What makes 4 color vision sex dependent is that the red sensor is on the X chromosome
- Men have 1 X chromosome, so they get 1 copy of the red gene, from their mother
- Women have 2 X chromosomes (1 from their mother, 1 from their father), so potentially they can inherit 2 different genes for red*
      - Because these genes may have different spectral responses, and are activated in different cone cells (due to "X inactivation") it is theoretically possible for some women to have better color discrimination than the usual 3 color vision
      - In practice, this has proven much more elusive than the genetics would suggest - perhaps because we educate it out of our girls?

* Incidentally, this explains why red/green color blindness is much more common in men than in women - women have a "backup copy" of the red gene, so if one copy is broken, the other copy usually still works.