Colorblindness is an interesting thing to most people because we wonder what it must be like to not distinguish some colors—a function of vision that we take for granted. Most people can live with colorblindness because it is present as soon as they are born and many go years without realizing that they do not see a full array of colors.
Certain tasks may be difficult or impossible, but even without seeing as many distinct colors as possible, these people function fine in everyday life. Colorblind tests exist to diagnose people who have color vision deficiency, and new advancements have even created eyewear to help people see more of the colors they are missing depending on their deficiency.
The cause of color blindness usually involves faulty cones. Cones are cells in your eyes that distinguish the three wavelengths of light that we see. Light can be split into red, green, and blue for the spectrum visible to humans. Color blindness can happen because the cone cells are faulty in some way and do not show distinct colors. A person may see shades of yellow and blue, for example, but have problems distinguishing red and green. Many people believe that color blindness means seeing only in black and white, but that is far more rare than typical color blindness.
Also, color deficiency is much more common in men than women. Only up to 1% of the female population has trouble seeing various colors, where somewhere between 8-12% of the male population is color blind.
Color blindness is usually an inherited genetic deficiency with the cones, but symptoms of color blindness may also occur due to stroke, old age, or a problem with pathways from the cones to the brain where the brain can determine colors.
More and more people are able to afford relatively new technology that helps us see more distinct colors. People who are not color blind can use special glasses to see a more saturated and distinct view of colors, but those with color deficiencies are seeing some colors that they have never seen before. These special color vision glasses are a favorite subject of YouTube videos where people give their friends the gift of color and film the shocking experience.
Curious about your own color perception? Learn more about it here (http://enchroma.com/test/instructions/), and test your color vision!