If you have ever considered flying planes as a career choice, you have probably heard that pilots are required to have excellent vision to fly aircraft safely, and that if a pilot has poor eyesight, he or she may not be able to pass the medical exam.
But how does color blindness factor into the ‘pilot’ equation? Can someone who has colorblindness successfully fly a plane?
And, in broader terms, how does color blindness affect the vision, and what are the different types of color blindness?
This article will answer all of these questions, and more.
Read on to learn all about the relationship between color blindness and aircraft regulations.
Can A Pilot Be Colorblind?
Yes – you may still be able to be a pilot if you are colorblind – but it does depend on a few different factors.
Really, it depends on the severity of your colorblindness, and what colors you have difficulty recognizing.
If you want to become a pilot in the US, then your vision and color blindness will be tested in your first Class One Medical assessment, which is one of the requirements to become a commercial airline pilot.
During the eyesight portion of this medical assessment, you will be presented with the Ishihara test, which consists of 24 plates (each of which has a number on it, and are presented in a randomized order), which you have to read out to the examiner.
For example, a plate might show a number 7, made out of red and green dots.
To pass the Ishihara color vision test, you have to correctly identify the numbers of 15 of the plates in a row.
The Ishihara test is the first test for the color vision requirements for operating a commercial aircraft – so if you pass, you don’t need to have any further color vision testing to be cleared to fly a plane.
If you fail the Ishihara test, you will need to go through more color testing before being cleared to fly.
This will establish if you have enough color vision requirements to fly a commercial aircraft.
However, this wasn’t always the case – up until very recently (2013 to be exact), if you showed signs of color blindness in the Ishihara test, you immediately failed the Class One Medical Assessment, and were disqualified from becoming a pilot on the grounds of poor vision.
However, as there have been advances in the field of optometry and color vision research, it is now possible to test for someone’s level of colorblindness.
Now, rather than being totally free of colorblindness, you just have to meet a minimum standard for color vision to become a pilot.
So, nowadays, it is possible to be issued a Class One Medical even with partial color blindness.
If you fail a color blindness test – you may still be able to fly, but there will be limitations on what you can do.
You may be barred from flying at night, or from color control signaling.
A Deeper Look At Colorblindness
Many men are colorblind (approximately 1 in 12), and they often have difficulty seeing reds and greens.
Colorblindness is a lot less common in women, with about 1 in 200 women having difficulties differentiating colors.
So, color blindness affects about eight per cent of men and 0.05 per cent of women in the U.S.
People with color blindness are usually unable to tell red from green or blue from yellow.
This means that if you have color blindness, you can easily get colors mixed up – which can cause mistakes when flying – as so many controls and signals are color coded.
There are three main types of colorblindness: red-green, blue-yellow, and monochromacy (also known as achromatopsia), which is incredibly rare.
The first two types are the most common forms of colorblindness.
Monochromacy is rarer than the other two types, but is the most dramatic, as people with this type of colorblindness cannot see any colors at all.
They do not even know they have a problem because they can’t tell which colors are missing from their world.
In fact, they might not even realize that there are colors around them until someone points out something that looks like a color to them.
It’s important to note that people with protanopia usually don’t lose their ability to distinguish shades of gray.
So, while they may not be able to recognize certain colors, they can still differentiate between light and dark.
When we talk about red-green colorblindness, we mean that the person is unable to distinguish between red and green objects.
There are for subsets of this kind of colorblindness:
– Protanopia (red-blind), where there are no red cone color receptors on the retina, and the individual cannot see the color red.
– Protanomaly (red weak), where there are some red cones, but fewer than normal, so an individual can see some but not all shades of red.
– Deuteranopia (green-blind), where there are no green cones in the retina, so individuals can’t see the color green.
– Deuteranomaly (green weak), where there are some green cones, but fewer than normal, so an individual can see some but not all shades of green.
The reason for this confusion is that our brains process information based on wavelength.
Red light waves are longer than green ones, so the brain processes them differently.
Because of this difference, people with red-green colorblindness often think that things are either red or green, but they actually aren’t, or confuse the two colors.
When we talk about blue-yellow colorblindness, we mean that the person is unable to distinguish between blue and yellow objects.
There are for subsets of this kind of colorblindness:
– Tritanopia (blue blind), where there are no blue cone color receptors on the retina, and the individual cannot see the color blue.
– Tritanomaly (blue weak), where there are some blue cones, but fewer than normal, so an individual can see some but not all shades of blue.
Blue-yellow colorblindness refers to the inability to distinguish between blue and yellow objects.
As mentioned earlier, the brain uses wavelength to determine what color something is.
Yellow light waves are shorter than those of blue, so the brain treats them differently.
Therefore, people with blue-yellow colorblindness can’t tell the difference between blue and yellow objects, such as blue skies versus yellow tinged clouds.
Monochromacy is where a person has only one type of cone cell, meaning that he/she has no rod cells (which are responsible for color vision).
This means that the person is completely colorblind – missing the capability to see colors, though they can still see light and dark.
People with this form of colorblindness are also known as achromats.
Some people with achromatism are born with it; others develop it later in life. It may occur at any age.
The cause of achromatism is unknown. Chromatopsia is a rare condition which causes achromatism.
In conclusion, the Ishihara Test is used to determine whether someone has color blindness, but if you are an aspiring pilot who has failed a color blindness test, don’t be immediately discouraged, as people who are color blind can fly planes.
The Ishihara Test helps determine if someone has sufficient color vision to safely fly a plane.
If you fail the Ishihara Test, you will be given additional testing to see if you have sufficient color vision to fly.