Monday, June 20, 2016

Is Color Blindness Recessive or Dominant?

Is Color Blindness Recessive or Dominant?

People who cannot tell the difference between colors which are evident to the rest people are assumed to have color blindness. For less sever deficiency, people usually don't know they have it until they confirm it through a lab test.


People often have different questions about color blindness, and among the most common questions is, "Is color blindness recessive or dominant?" Before this question, how much do you know about color blindness?


For inherited color blindness, the underlying cause is abnormal photo pigments. Located within the retina of your eye, the the color-detecting molecules are called cone cells. And people needseveral genes to make these photo pigments, and any defect in these genes lead to color blindness.


Is Color Blindness Recessive or Dominant?


Color blindness is basically a recessive condition linked to sex – it is transmitted in the 23 pair of chromosomes, which are spaghetti-like strands packed with genetic info. A normal person will have 23 pair of chromosomes in all cells other than sex cells. Males will have one X chromosome and one Y chromosome in the 23rd pair of chromosomes, whereas females will have two X chromosomes only.


Since color blindness transmits via X chromosomes, it is therefore called a recessive trait. Any recessive trait will need two recessive genes of an organism to manifest that characteristic.


What Causes Color Blindness?
Most problems related to color vision are hereditary in nature and are present at birth. Every normal person has 3 types of cone cells in the retina, and these cones can sense blue, green, or red light. You can only see colors if your cone cells could sense different amounts of 3 basic colors. Sometimes, you don't have any of these cones, or they don't function properly. It means, you may find it difficult to identify 1 of these 3 colors or mistake the 3 colors.


Your color vision problem is not always related to genetics, and other factors can also affect the way you perceive colors. The factors include injury to the eye, aging, side effects of some medicines, and eye problemssuch as Macular Degeneration, Glaucoma, diabetic retinopathy, and cataracts.


Any chemical or physical damage to the eye may also lead to color blindness. It may also result from any damage to the optic nerve or part of the brain that deals with color information.


Can Color Blindness Be Treated?
Now you already have the answer to your question, "Is color blindness recessive or dominant?" You may have another question, "Is it possible to treat color vision problems?" In case, your color blindness involves genetics, you cannot do anything to fix the issue. You don't need a treatment though if you're suffering from the most common type of color blindness, called red-green color deficiency, because it doesn't interfere with your normal life. In fact, you may not even know you have this type of color blindness.


However, you can find a treatment option for some acquired color vision problems. And it will depend on the underlying cause of color blindness. For instance, you can have your cataract removed if it's affecting your color vision. Here are some possible options to handle color vision problems.



  • Your doctor may recommend wearing colored contact lenses, so you could see differences between different colors. Unfortunately though, these lenses can distort objects.

  • You may consider wearing glasses designed specifically to block glare because most people can notice some color difference when there is less brightness or glare.

  • You can also learn how to use cues like location or brightness rather than colors to manage things better in your life.


Types of Color Blindness
Is color blindness recessive or dominant? You already know it, and now you will want to learn a bit more about types of color blindness to better understand the whole issue.Depending on the photo pigment defects in different kinds of cells, you can divide color blindness in three categories: red-green color blindness, blue-green color blindness, and a complete absence of color vision which is the rarest of all three types.


Red-Green Color Blindness
It is the most common types of hereditary color vision problem and refers to a situation where your red cone or green cone photo pigments don't work at all.


When the red cone photo pigment is abnormal, it's called protanomaly. You will find colors less bright with orange, red and yellow appearing greener. Potanomaly is an X-linked condition that can affect 1% of males.


The absence of working red cone cells in male refers to the condition called protanopia. In this X-linked disorder, red will appear as black and certain shades of yellow, orange, and green will all appear as yellow. Protanopia is an X-linked condition and can affect 1% of males.


When the green cone photo pigment isn't normal in males, this condition is called deuteranomaly in which green and yellow appear redder. This is the most common color blindness form that can affect 5% males.


The absence of any working green cone cells is referred to as deuteranopia in which reds will look more as brownish-yellow.


Blue-Yellow Color Blindness
It's also quite common but rare than red-green color blindness.


You will be a patient of tritanomaly if your blue cone cells aren't fully functional. In this extremely rare condition, blue will appear greener, and you will have a hard time differentiating between yellow and pink.


You're suffering from tritanopia if blue appears green and yellow looks more as violet. That's mainly because you don't have any blue cone cells. This autosomal recessive disorder affects both males and females.


Complete Color Blindness
You're a patient of complete color blindness if you cannot experience any color at all. There are two basic types of complete color blindness.



  • Cone Monochromacy: When two out of three cone cell photo pigments don't work, this leads to cone monochromacy. It is essential for your brain to compare color signals from all three cones to make it possible for you to identify colors. This doesn't happen when you have cone monochromacy. The condition will also cause other issues, such as near sightedness, reduced visual acuity, and uncontrollable eye movements.

  • Rod Monochromacy: This is the most severe form of monochromacy but is quite rare too. In this condition, you won't have any functional photo pigments, which means you will only see the world in three colors – gray, white, and black.


You can take a test HERE to see if you are color blindness.

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