COLOR BLINDNESS - It's not just for grownups!
Color blindness is often not recognized until later in life when applying for jobs that rely on being able to distinguish colors clearly. I wanted to help you with insights into color blindness, as it can be diagnosed early, and accomodations for your child can be made before school entry.
First, how early in life can children see in color?
Roughly around 4-6 months – as children start to pick up objects in the distance, and see clearly up close, their world also transforms to full living color – sort of like how Dorothy started in black and white Kansas, and then saw Oz glimmering in the distance in color!
When can kids start to distinguish colors? And how can we best teach them?
First, In order to actively teach our children colors we should start as they start acquiring language. Some interesting studies at Stanford University revealed that kids will learn colors sooner and more accurately, if the object of interest is of interest to them.
For example saying “Blue sky” may not evoke memory of Blue to a kid who could care less about the sky – but the Balloon (fun!) that is blue might. So naming an object of interest, followed by “Yes, that is a balloon that is blue will imprint on their brains more significantly. Most kids can name 1 color or 2 by 2-3 years of age, and certainly by 5-6 should be able to run through the usual Crayola 8 basic colors without too much problem.
How common is color blindness?
It affects 1/12 males and 1/200 females worldwide. In the US that would translate to 12,650,000 males opposed to 785,000 females.
What causes color blindness?
The retina of the eye has two types of light-sensitive cells called rods and cones. Both are found in the retina which is the layer at the back of your eye which processes images. Rods work in low light conditions to help night vision, and are more in the periphery of the retina; but cones work in daylight and are responsible for colour discrimination and are directly in the path of most light coming in to the center of the retina.
There are three types of cone cells and each type has a different sensitivity to light wavelengths. One type of cone perceives blue light, another perceives green and the third perceives red. When you look at an object, light enters your eye and stimulates the cone cells. Your brain then interprets the signals from the cones cells so that you can see the color of the object. The red, green and blue cones all work together allowing you to see the whole spectrum of colors.
People with normal color vision have all three types of cone/pathway working correctly but color blindness occurs when one or more of the cone types are faulty. Typically these defects run in families – are more typical in males, but passed down on the maternal side of the family.
So when do we suspect a child is color blind, and by what age?
Typically by 5-6 years of age, and here are some typical observations in children who are color blind:
- using the wrong colors for an object – e.g. purple leaves on trees, particularly using dark colors inappropriately
- frustration or poor attention when coloring – it’s just not that interesting
- problems in identifying red or green or other colors with those tones – ie purple and brown
- when lights are dim, trouble distinguishing colors
- smelling food before eating – it’s hard to tell what veggie is what!
- excellent sense of smell
- excellent night vision – as the rods are very strong
- sensitivity to bright lights
- trouble reading colored letters
- head or eye-ache when looking at red or green backgrounds
- difficulty grouping objects with similar/overlapping colors
How can we test for it?
Now there are visual cards called “Color Vision Testing Made Easy” that are highly sensitive to recognizing color visual deficits - they are geared to 3-6 year olds but very useful for those with developmental handicaps and for those who have trouble with numbers. This tests relies on recognition of common shapes – circles, stars , squares, etc.. Results of studies have shown high sensitivity of detection.
And if a child is color blind, what can you do?
It is important that the specific type of color blind condition is diagnosed professionally because
(i) support provided in school needs to be tailored to suit each specific condition – ie a child with color blindness shouldn’t be penalized academically if color-oriented tasks are not passed) and
(ii) the type of color blind condition someone has may affect their ability to pursue certain careers – like aviation, electrical work, bomb squads, firefighting, operating motor vehicles, baggage handling, peace officers (police), and painters