Interesting Facts – Chapter 9
5 Facts About Color Blindness 👁
Let's explore color vision deficiency – also known as color blindness 😃👁
Cucumbers are green and poppies are red. For most people, color is something we never even think about. But some people go through life without seeing certain colors. About 8 in every 100 men and 1 in every 200 women know some colors only by name. Color vision deficiency comes in different levels – from total color blindness, where everything looks black, gray and white, to just mixing up red and green.
1) The cells that sense color:
To see colors properly, the eye has to detect colors correctly and tell them apart. To do that, a healthy eye
has three kinds of color-sensing cells in its retina. With them, the eye picks up the three main colors – red, green and blue – and mixes them into millions of different shades.
2) Levels of color blindness:
In people with color vision deficiency, one, two or all three kinds of color-sensing cells don’t work, or work only partly. That’s why they can’t see certain colors.
In total color blindness, none of the three kinds of cells work, so everything looks like a black-and-white picture in shades of gray.
In partial color blindness, one or two of the three kinds of cells don’t work, so some of the main colors are missing.
In color confusion, the cells work but are less sensitive, so colors get mixed up in some situations – for example, if the red-sensing cells are weaker, a red traffic light may be hard to tell from a green one.
Red-green color blindness is the most common type – it makes up about 60% of cases – and it’s much more common in boys.
Blue color blindness is rarer. In this case the blue-sensing cells are weaker, and people find it hard to see blue or to recognize yellow.
3) What causes color vision deficiency?
Color vision deficiency is usually inherited – passed down in families. In that case it doesn’t get better or worse over time. But sometimes trouble seeing colors develops later in life.
Some illnesses, like diabetes, retinal disease or Parkinson’s disease, can affect color vision. Sometimes one eye is affected more than the other, and color vision may improve if the illness can be treated.
Certain medicines, such as some heart and blood-pressure medicines, can also change how people see colors.
And as people grow older, their ability to see colors can slowly fade.
4) How is color blindness tested?
Color vision is usually tested with special cards covered in colored dots. Kids can take the test from about age 3.
People with partial color blindness can still see colors, but they see shades differently – as if their paint box had fewer main colors to mix than other people’s. And it’s not all bad – some things actually stand out better or with more contrast for them.
One of the first signs of red-green color blindness is having trouble coloring with the right colors or telling traffic lights apart.
Test yourself! Look at the circles and tell someone next to you which colors you see.
5) Treatment: what can help with color blindness?
There’s no cure for color blindness people are born with – surgery or similar treatments aren’t possible. But in some cases, a few things can help.
People with total color blindness often wear dark sunglasses with special filters that block certain colors of sunlight, depending on the light. A magnifying glass or small binoculars can help them read small print or see far away.
For people with red-green color blindness, there are glasses with special lenses that filter certain colors differently – though they also change how other colors look.
People with color blindness live full, normal lives, though those with total color blindness are often very sensitive to bright light. Sometimes they might end up wearing colors that don’t quite match – oops! And because some jobs depend on telling colors apart, certain careers, like being an airline pilot, can be harder for them.
