# side note on color blindness **URL:** \ **Category:** Cecil's Columns/Staff Reports\ **Created:** [March 9, 2012, 6:55am UTC](https://boards.straightdope.com/t/side-note-on-color-blindness/615239 "2012-03-09T06:55:42Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![Jerry\_in\_Canada](https://avatars.discourse-cdn.com/v4/letter/j/e495f1/32.png) [@Jerry\_in\_Canada](https://boards.straightdope.com/u/Jerry_in_Canada)\ **Post date:** [March 9, 2012, 6:55am UTC](https://boards.straightdope.com/t/side-note-on-color-blindness/615239/1 "2012-03-09T06:55:42Z")
I recall seeing an article several years ago about a farmer in Saskatchewan (one of the new ones with a university degree) who had discovered a way to filter out the reflected wavelength of chlorophyll and developed a pair of sunglasses that allowed him to see diseased or infested plants long before they were visible to the naked eye, by removing the color of chlorophyll all of the foliage reverted to it’s autumn coloration revealing significant changes in color that were masked by the chlorophyll green. As an unexpected side bonus, the American military was said to have bought up the whole process, patents, models and experimental models; and the whole thing dropped off of the radar. I can see why: I saw one image taken of a Tank, a 105mm Howitzer and a Truck at the edge if a field, in a treeline and covered all in Forest Camo Net. In normal color they were practically invisible. Filtered they stood out green against a background of yellow and orange; and you go back to the normal color and NOW you can see them. Can you verify any of this ? Thanks Jerry in Canada * * * LINK TO COLUMN: [Is colorblindness an evolutionary advantage? - The Straight Dope](http://www.straightdope.com/columns/read/3037/is-colorblindness-an-evolutionary-advantage) ---
**Author:** ![sitchensis](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sitchensis/32/4892_2.png) [@sitchensis](https://boards.straightdope.com/u/sitchensis)\ **Post date:** [March 9, 2012, 7:29am UTC](https://boards.straightdope.com/t/side-note-on-color-blindness/615239/2 "2012-03-09T07:29:24Z")
I believe what you are talking about is infrared mapping. It has been used by the military in the past, but I don’t believe it is used very much today, thermal images seem to have surpassed infrared for military uses. Infrared photography can still be very useful in agriculture, in mapping moisture distribution on irrigated fields and in mapping certain types of plants for invasive and noxious weed studies. ---
**Author:** ![gnoitall](https://avatars.discourse-cdn.com/v4/letter/g/bb73d2/32.png) [@gnoitall](https://boards.straightdope.com/u/gnoitall)\ **Post date:** [March 9, 2012, 10:09pm UTC](https://boards.straightdope.com/t/side-note-on-color-blindness/615239/3 "2012-03-09T22:09:35Z")
> [@sitchensis](#): > > I believe what you are talking about is infrared mapping. It has been used by the military in the past, but I don’t believe it is used very much today, thermal images seem to have surpassed infrared for military uses. Infrared photography can still be very useful in agriculture, in mapping moisture distribution on irrigated fields and in mapping certain types of plants for invasive and noxious weed studies. Many Earth-observing climate/weather satellites use combinations of infrared and visual light imaging (plus quite interesting processing algorithms) to detect the type and state of health of vegetation. Going waaaaay back to Landsat in the 1970s. The selective use of visual light spectra along with IR is just a very sophisticated application of color-filtering sunglasses, if you think about it. ETA: Here’s the Landsat program’s page about [agricultural applications](http://landsat.gsfc.nasa.gov/about/Application1.3.html) of Landsat sensing. ---
**Author:** ![njtt](https://avatars.discourse-cdn.com/v4/letter/n/ecd19e/32.png) [@njtt](https://boards.straightdope.com/u/njtt)\ **Post date:** [March 12, 2012, 11:29pm UTC](https://boards.straightdope.com/t/side-note-on-color-blindness/615239/4 "2012-03-12T23:29:25Z")
Clearly, **Jerry in Canada** ’s story about the farmer in Saskatchewan has nothing to do with infra-red sensing. Glasses that filter out the wavelength of chlorophyll will not somehow make the eyes sensitive to infra-red. Incidentally, **sitchensis** , I am pretty sure that infra-red sensing/photography and thermal imaging are (in this context) exactly the same thing. And > [@gnoitall](#): > > The selective use of visual light spectra along with IR is just a very sophisticated application of color-filtering sunglasses, if you think about it. as the human eye is insensitive (by definition) to infra-red, no it isn’t, if you actually do think about it.