- Reaction score
- 0
- Points
- 410
Blakey: Yes, colour vision is not a requirement to be in the infantry.
- Reaction score
- 1
- Points
- 410
Colour Vision Categories and the Canadian Forces
BACKGROUND:
The light detectors in the human retina consist of rod shaped detectors that work best in low light conditions and three types of cone shaped elements misleadingly called red, green, and blue. The output from these three detectors is encoded by the retina before a coded signal is sent via the optic nerves to the brain. The brightness and colour signals travel within parallel but separate nerves and the signals are then decoded and processed in the brain. At this stage colour memory, context, and other factors modify the perception. After this interpretation of the decoded signal in the brain we "see" a colour attribute within the object we are looking at.
Source: http://www.cleareyeclinic.com/col_vis.html#col_vis_top
Color blindness is rooted in the chromosomal differences between males and females. Females may be carriers of color blindness, but males are more commonly affected. About 8 percent of males and 0.5 percent of females are color deficient.
Color blindness is a malfunction of the retina, which converts light energy into electircal energy that is then transmitted to the brain. This conversion is accomplished by two types of photoreceptor cells in the retina: rods and cones.
The cones are responsible for encoding color. Each cone contains structures or visual pigments sensitive to one of three wavelengths of light: red, green, and blue. Normal persons are able to match all colors of the spectrum by mixtures of only three fundamental color sensitivities. Hence, the huge variety of colors we perceive stems from the cone cells' response to different compositions of wavelengths of light.
Defects in color vision occur when one of the three cone cell color coding structures fails to function properly. One of the visual pigments may be present and functioning abnormally, or it may be absent altogether.
For practical purposes, all color-deficient individuals have varieties of red or green deficiency. Blue deficiencies are very rare. Color deficient patients are not completely red or green blind. Compared to persons with normal color vision, they have some trouble differentiating between certain colors, but the severity of the color deficiency is variable.
Source: http://www.zipmall.com/mpm-art-colorbl.htm
RGB & CONES:
The 3 cone types are - short wavelength (S) or blue cones 420nm; middle wavelength (M) or green cones 534nm; and long wavelength (L) or red cones 564nm. The peak sensitivity of rods is 498nm. Each cone contains the same chromophore - 11 cis-retinal â “ attached to one of three opsins. Small variations in the amino acid sequence of these opsins are responsible for the spectral tuning of the receptors, and abnormalities in these opsins account for the various congenital colour vision anomalies.
TERMS
Protan (root: proto - single or one)
Deutan (root: dual - two)
Tritan (root: triple - three)
Protanopes (Protan) The long cones (red) do not work. medium cones are working. Affects 2% of men. They confuse similar green-blue with a red-purple (exhibit a confusion axis from red to blue-green). Reds appear dark.
Deuteranopes (Deutran) The long and medium cones do not work (red and green). Affects 6% of men. They confuse a green-blue colour with a blue-purple (exhibit a confusion axis from green to purple).
Tritanopia (Tritan) Is rare and normally disease induced. The short cones do not work (blue). It does not mean the long and medium cones do not work.
Achromats (exceptionally rare) No colour - true black and white (greyscale) vision.
An example axis chart for the Farnsworth test is show at the bottom of this page:
http://www.forces.gc.ca/health/policies/med_standards/pdf/Engraph/cfp154_annexBappen1_e.pdf
Example images showing the different colour deficiencies of Protan and Deutan with Normal CV:
http://www.tsi.enst.fr/~brettel/colourblindness.html
MEDICAL STANDARDS FOR THE CANADIAN FORCES
Colour vision measurement refers to the eye in its normal state and not to measurement through coloured contact lenses designed to "correct" colour vision defects. The instructions for the testing of colour vision are shown at Annex B CFP-154. Three grades of colour vision are recognized: CV1, CV2 and CV3.
Extracted from Annex B, CFP-154:
1. The most common form of colour deficiency (blindness) is a recessive sex-linked hereditary
defect which normally affects only males. About 8-10% of males and 0.4-0.8% of females are
colour deficient.
2. The three (3) possible grades of colour vision are:
a. CV1 - Colour Vision Normal
b. CV2 - Colour Vision Safe; and
c. CV3 - Colour Vision Unsafe.
3. Initially, recruits and serving members will be tested using the Ishihara pseudoisochromatic
plates in accordance with the plate instructions. Those who fail this colour plate test will be tested
with the Farnsworth Panel D-15 test. Both of these tests are available at CF Recruiting Centres
(CFRC). If any problem in interpretation of the CV grading occurs, consultation with the
Department of Ophthalmology at National Defence Medical Centre (NDMC) is recommended.
4. Assessment of colour vision by either the Holmes-Wright or Farnsworth Colour perception
lanterns will only be conducted at NDMC and/or the Defence and Civil Institute of Environment
Medicine (DCIEM) for selected MOCs. The colour lanterns are no longer used as secondary tests
for those who fail the Ishihara colour plates, except for aircrew applicants.
You can check minimum medical category (including colour vision) for each trade by clicking here:
http://www.forces.gc.ca/health/policies/med_standards/pdf/engraph/cfp154_annexEappen1-2_e.pdf
To determine if your CV1, your given the Ishihara panel test. If you pass this test,
your CV1 Colour Vision Normal.
Ishihara Panel test - 6 examples only. Sets are of 24 or 38 panels. The full test in the CF is
the first 21 panels in the 24 set.
http://www.toledo-bend.com/colorblind/Ishihara.html
If you fail the panel test, you will be tested on the Farnsworth Panel D-15 Test. This
will determine if your CV2 or CV3.
extracts from CFP-154:
The tester arranges the 15 coloured caps in random order,
coloured sides up and test numbers down, in the lid of the test kit case. The fixed cap, a reference
cap, at the left of the case, should be situated near the examinee and on his/her left. It is most
convenient for the tester to sit across a table from the examinee.
10. The test procedure must be explained to the examinee. Starting from the fixed (reference) cap
the examinee is to rearrange the caps, step by step, in order of colour hue. The testing time is two
(2) minutes, and persons who finish very quickly should be asked to check their ordering.
11. To score (correct) the test, the person giving the test simply closes the lid, turns the case
upside down and reopens the lid of the case. If done correctly, the numbers on the caps should
now be readable.
13. The interpretation of the test results is simple if no errors were made in the ordering of the
coloured caps; a grade of CV2, colour vision safe, would be assigned.
If you fail this test (make major errors), you are assigned CV3 Colour Vision Unsafe (Deutan).
BACKGROUND:
The light detectors in the human retina consist of rod shaped detectors that work best in low light conditions and three types of cone shaped elements misleadingly called red, green, and blue. The output from these three detectors is encoded by the retina before a coded signal is sent via the optic nerves to the brain. The brightness and colour signals travel within parallel but separate nerves and the signals are then decoded and processed in the brain. At this stage colour memory, context, and other factors modify the perception. After this interpretation of the decoded signal in the brain we "see" a colour attribute within the object we are looking at.
Source: http://www.cleareyeclinic.com/col_vis.html#col_vis_top
Color blindness is rooted in the chromosomal differences between males and females. Females may be carriers of color blindness, but males are more commonly affected. About 8 percent of males and 0.5 percent of females are color deficient.
Color blindness is a malfunction of the retina, which converts light energy into electircal energy that is then transmitted to the brain. This conversion is accomplished by two types of photoreceptor cells in the retina: rods and cones.
The cones are responsible for encoding color. Each cone contains structures or visual pigments sensitive to one of three wavelengths of light: red, green, and blue. Normal persons are able to match all colors of the spectrum by mixtures of only three fundamental color sensitivities. Hence, the huge variety of colors we perceive stems from the cone cells' response to different compositions of wavelengths of light.
Defects in color vision occur when one of the three cone cell color coding structures fails to function properly. One of the visual pigments may be present and functioning abnormally, or it may be absent altogether.
For practical purposes, all color-deficient individuals have varieties of red or green deficiency. Blue deficiencies are very rare. Color deficient patients are not completely red or green blind. Compared to persons with normal color vision, they have some trouble differentiating between certain colors, but the severity of the color deficiency is variable.
Source: http://www.zipmall.com/mpm-art-colorbl.htm
RGB & CONES:
The 3 cone types are - short wavelength (S) or blue cones 420nm; middle wavelength (M) or green cones 534nm; and long wavelength (L) or red cones 564nm. The peak sensitivity of rods is 498nm. Each cone contains the same chromophore - 11 cis-retinal â “ attached to one of three opsins. Small variations in the amino acid sequence of these opsins are responsible for the spectral tuning of the receptors, and abnormalities in these opsins account for the various congenital colour vision anomalies.
TERMS
Protan (root: proto - single or one)
Deutan (root: dual - two)
Tritan (root: triple - three)
Protanopes (Protan) The long cones (red) do not work. medium cones are working. Affects 2% of men. They confuse similar green-blue with a red-purple (exhibit a confusion axis from red to blue-green). Reds appear dark.
Deuteranopes (Deutran) The long and medium cones do not work (red and green). Affects 6% of men. They confuse a green-blue colour with a blue-purple (exhibit a confusion axis from green to purple).
Tritanopia (Tritan) Is rare and normally disease induced. The short cones do not work (blue). It does not mean the long and medium cones do not work.
Achromats (exceptionally rare) No colour - true black and white (greyscale) vision.
An example axis chart for the Farnsworth test is show at the bottom of this page:
http://www.forces.gc.ca/health/policies/med_standards/pdf/Engraph/cfp154_annexBappen1_e.pdf
Example images showing the different colour deficiencies of Protan and Deutan with Normal CV:
http://www.tsi.enst.fr/~brettel/colourblindness.html
MEDICAL STANDARDS FOR THE CANADIAN FORCES
Colour vision measurement refers to the eye in its normal state and not to measurement through coloured contact lenses designed to "correct" colour vision defects. The instructions for the testing of colour vision are shown at Annex B CFP-154. Three grades of colour vision are recognized: CV1, CV2 and CV3.
Extracted from Annex B, CFP-154:
1. The most common form of colour deficiency (blindness) is a recessive sex-linked hereditary
defect which normally affects only males. About 8-10% of males and 0.4-0.8% of females are
colour deficient.
2. The three (3) possible grades of colour vision are:
a. CV1 - Colour Vision Normal
b. CV2 - Colour Vision Safe; and
c. CV3 - Colour Vision Unsafe.
3. Initially, recruits and serving members will be tested using the Ishihara pseudoisochromatic
plates in accordance with the plate instructions. Those who fail this colour plate test will be tested
with the Farnsworth Panel D-15 test. Both of these tests are available at CF Recruiting Centres
(CFRC). If any problem in interpretation of the CV grading occurs, consultation with the
Department of Ophthalmology at National Defence Medical Centre (NDMC) is recommended.
4. Assessment of colour vision by either the Holmes-Wright or Farnsworth Colour perception
lanterns will only be conducted at NDMC and/or the Defence and Civil Institute of Environment
Medicine (DCIEM) for selected MOCs. The colour lanterns are no longer used as secondary tests
for those who fail the Ishihara colour plates, except for aircrew applicants.
You can check minimum medical category (including colour vision) for each trade by clicking here:
http://www.forces.gc.ca/health/policies/med_standards/pdf/engraph/cfp154_annexEappen1-2_e.pdf
To determine if your CV1, your given the Ishihara panel test. If you pass this test,
your CV1 Colour Vision Normal.
Ishihara Panel test - 6 examples only. Sets are of 24 or 38 panels. The full test in the CF is
the first 21 panels in the 24 set.
http://www.toledo-bend.com/colorblind/Ishihara.html
If you fail the panel test, you will be tested on the Farnsworth Panel D-15 Test. This
will determine if your CV2 or CV3.
extracts from CFP-154:
The tester arranges the 15 coloured caps in random order,
coloured sides up and test numbers down, in the lid of the test kit case. The fixed cap, a reference
cap, at the left of the case, should be situated near the examinee and on his/her left. It is most
convenient for the tester to sit across a table from the examinee.
10. The test procedure must be explained to the examinee. Starting from the fixed (reference) cap
the examinee is to rearrange the caps, step by step, in order of colour hue. The testing time is two
(2) minutes, and persons who finish very quickly should be asked to check their ordering.
11. To score (correct) the test, the person giving the test simply closes the lid, turns the case
upside down and reopens the lid of the case. If done correctly, the numbers on the caps should
now be readable.
13. The interpretation of the test results is simple if no errors were made in the ordering of the
coloured caps; a grade of CV2, colour vision safe, would be assigned.
If you fail this test (make major errors), you are assigned CV3 Colour Vision Unsafe (Deutan).
Hi There,
You guys are so lucky to be able to get into an interesting position in the Army in Canada,while having a colour deficiency.
I was reading another post by someone who has the same colour deficiency that I do - deutan (normal red vision but deficient green) - who is still able to get into the Army in a signals role.
I have been trying to get into the Australian Army for 18months now, also in a signals role, going back to school and upgrading my education level, only to find out that I had this deficiency - after making it through the last 33 years and not knowing it - and to see my application rejected!
When I appealed this and asked about other positions, explaining that I have no drama with red - the "danger" colour, and the more important colour to see - I was advised that the most exciting position I can hope to obtain will be working behind a desk because I am "partially blind to the colour green".
So much for looking for a career with a bit of excitement.
Good luck to anyone able to join the Canadian Army with this problem, it kind of shows the Canadian Army is a little more progressive than the Australians...
Cheers.
You guys are so lucky to be able to get into an interesting position in the Army in Canada,while having a colour deficiency.
I was reading another post by someone who has the same colour deficiency that I do - deutan (normal red vision but deficient green) - who is still able to get into the Army in a signals role.
I have been trying to get into the Australian Army for 18months now, also in a signals role, going back to school and upgrading my education level, only to find out that I had this deficiency - after making it through the last 33 years and not knowing it - and to see my application rejected!
When I appealed this and asked about other positions, explaining that I have no drama with red - the "danger" colour, and the more important colour to see - I was advised that the most exciting position I can hope to obtain will be working behind a desk because I am "partially blind to the colour green".
So much for looking for a career with a bit of excitement.
Good luck to anyone able to join the Canadian Army with this problem, it kind of shows the Canadian Army is a little more progressive than the Australians...
Cheers.
- Reaction score
- 0
- Points
- 60
I am strongly considering joining the Army. I have heard that lots of people in their 30's join and have no problem in basic. I am 21 and just wondering if age puts any restraints on a potential career. As well I am colour blind and wondering if that will exclude me all together, and am un-able to find any information on this??
Any input would be great!!
Thanks.
Any input would be great!!
Thanks.
- Reaction score
- 5
- Points
- 430
That will most likely depend on exactly what form of colourblindness he has, and what trade(s) he is interested in.
Until one of the meics can add some more info, this thread from the Canadian Forces Medical Group board may help:
Color Blindness... - http://army.ca/forums/threads/26420.0.html
Until one of the meics can add some more info, this thread from the Canadian Forces Medical Group board may help:
Color Blindness... - http://army.ca/forums/threads/26420.0.html
- Reaction score
- 0
- Points
- 210
I think for Pilot specifically you need C2 color vision, which is the 2nd highest notch in color vision. So he probably cannot go that route, but I think lots of other trades aren't quite as picky.
- Reaction score
- 0
- Points
- 110
my father is an AVN tech and has slight colorblindness. as was said it deppends on what lever of colorblindness he has and what trade he wants to apply for. I'm sure he would have no problem getting in assuming thats the only thing wrong, but it may not be a trade he is interessted in.
- Reaction score
- 0
- Points
- 210
I hate to revive this old dinosaur, but the link to the medical annex E with the PDF considering the MOCs can't be found, and i've searched here and the DND site but can't seem to find it. Does anyone know where i can?
FormerHorseGuard
Sr. Member
- Reaction score
- 422
- Points
- 760
i was in the service and am a semi expert on being colour blind while being in the army at the same time.
i am cv3 for my own safety i have less trouble tellinng a person what colours i see then those i do not see correctly. too many colours give me problems
trades that were closed to me were the following:
any arty trades, more of safety thing then not being able to see the pull the layard. the ammo is marked in colour codes and the safety zone markings , i am guessing some sort of lights used.
sigs was out because of the lights used and wires colour coding.
all air crew positions, all due to a light safety thing
navy trades for the most part closed
was never told if i could of been n engineer
MP was out, for various reasons, unable to show that the car i was chasing was the correct colour and stuff in court if need be.
i was able to be a grunt, supply tech, fin clerk, admin clerk,medic,armoured crewman, mseop and some others
check with your recruiting person for the trades open to your CV level.
good luck, and do not sweat the colour tests. i was tested twice, once on my first physical then sent to a specialist for more testing and once later by DCIEM and aircrew selection , the latern test is harder then any book test.
good luck in the military
i am cv3 for my own safety i have less trouble tellinng a person what colours i see then those i do not see correctly. too many colours give me problems
trades that were closed to me were the following:
any arty trades, more of safety thing then not being able to see the pull the layard. the ammo is marked in colour codes and the safety zone markings , i am guessing some sort of lights used.
sigs was out because of the lights used and wires colour coding.
all air crew positions, all due to a light safety thing
navy trades for the most part closed
was never told if i could of been n engineer
MP was out, for various reasons, unable to show that the car i was chasing was the correct colour and stuff in court if need be.
i was able to be a grunt, supply tech, fin clerk, admin clerk,medic,armoured crewman, mseop and some others
check with your recruiting person for the trades open to your CV level.
good luck, and do not sweat the colour tests. i was tested twice, once on my first physical then sent to a specialist for more testing and once later by DCIEM and aircrew selection , the latern test is harder then any book test.
good luck in the military
FormerHorseGuard
Sr. Member
- Reaction score
- 422
- Points
- 760
my first moc was r031 and i am cv 3. so yes it is possbile
- Reaction score
- 0
- Points
- 210
i heard you need CV 2 for reg force Inf. I'm probly wrong though, CV3 is fine for R031 how ever.
- Reaction score
- 0
- Points
- 210
i have been told that with colour pigment deficiency's your night vision is better? is this true, or just a myth? 
