why does blood look blue when it is in fact red?
461959
It is blue when the blood does not have oxygen in it.  Once blood is drawn though, it hits the oxygen and turns red.
442051
simple boss... eyes become red because the nerves in the eyes get strained. if u concentrate on a part of the body and strain it ... u can make it become red. look constantly at the same point. that strains ur eyes muscles and the blood pressure increses in the eyes. thus they become red.
410647
It's really blue. Because you see it as blue.
156204
I don't believe that guy called her a moron for giving the right answer. Yes blood without oxygen is blue but it may appear green due to you looking at it through your skin. I'm sure you've seen someone with blue lines on their body. When blood becomes oxygenated...the Fe is pulled to the center of the heme ring. It's actually this conformational change that produces the red color. Not rust. Also to comment. The Fe is contained within the porphyrin ring but not in a flat structure. It is partially off center and is pulled more equally within the ring structure with the addition of oxygen. If you looked it up you'd know I wasn't making **** up. Although i do apologize for the blue comment. But we see blue because of the absorption of light at the surface of our skin. At least while the blood is stil in circulation. You need to be less critical. Yes all of them are red but to the naked eye under the skin they clearly appear blue. It's not total "bullocks" for someone to assume such. The intelligent should learn to be teachers not arrogant tactless shrews.
474322
Red is blood of all creatures.\n\nGreen is seen as tranquil to go in peace.
56806
The phrase "blue blood" is used to mean "from an aristocratic background," because pale, untanned skin–a sign of nobility–allows blue-tinged veins to show through.\n\nThat may be a probable reason for this phrase..
228065
Look down there..\nThe *.pdf is most detailed and informative.\n\nI am stunned at the total lack of sense displayed by some of these answers! Blood is red! Oxygen poor blood is more 'purpley' in colour but not blue. NONE OF THE BLOOD CIRCULATING INSIDE YOUR BODY IS BLUE!!!
94518
All blood is red. Blood with oxygen has a lighter/brighter color, while blood without oxygen is more of a purpleish tint. It does not change color completely from blue to red. This is a common misconseption given from the fact that many charts use red and blue to show clearly which blood streams are which. The vein is greenish because of the many colors in your body combined. The skin, blood itself, and many other things contribute to this. I don't know about live veins, but I know the ones in stuff like meat are white, not green.
219455
because blood is blue.\n\nit only turns red when it oxidates/coagulates with oxygen.
586396
(m)\n\nLimulus is a true "blue blood" for, while human blood is red, the blood of this creature is a light blue.  Human blood is red because it has a red pigment called hemoglobin which contains iron.  The Limulus blood contains copper rather than hemoglobin thus giving the blood its blue color.  The animal's blood also contains fantastically sensitive chemicals used by researchers in discovering harmful bacteria called endotoxins, sometimes found in human blood.  In short, the blood of this ancient animal might well save your life some day.
461513
I dont think you can. =^P It would be wierd if I was seeing blue and somebody else was seeing (my version of) red and saying it was blue... Mabye everybody has different color views. Never know.
646815
it's not actually, if you look at the ocean, from the top it is blue becaues it is reflecting the light from the sky.   if you are underwater, it looks blue because the blue light is dispersed the least, meaning that the blue light penetrates farther into the water than the other colors of light.
280752
When the blood is returning to the heart through veins, it is blue because it has delivered its oxegyn and nutrients.  Once it returns to the heart and starts making its trip back through arteries, it is red again.\n\nBlood exposed to the outside air will always retain its red color, even if a vein is severed because once it leaves the body, oxygen in the air will change it back to red.
1139400
In the circulatory system, venous blood or peripheral blood is blood returning to the heart. With one exception (the pulmonary vein) this blood is deoxygenated and high in carbon dioxide, having released oxygen and absorbed CO2 in the tissues. It is also typically warmer than arterial blood, has a lower pH, has lower concentrations of glucose and other nutrients, and has higher concentrations of urea and other waste products.\n\nVenous blood can be obtained by venesection or phlebotomy, or in small quantities by fingerprick. Most medical laboratory tests are conducted on venous blood, with the exception of arterial blood gases.\n\nVenous blood is often depicted as blue in color in medical diagrams, and veins sometimes look blue when seen through the skin. However, venous blood is actually a dark red color, while arterial blood is bright red. The appearance of blood as dark blue is a wavelength phenomenon of light, having to do with the reflection of blue light away from the outside of venous tissue if the vein is @ 0.02in deep or more. This is due to the difference in color between deoxyhemoglobin and oxyhemoglobin; the red color ultimately originates from the iron atom in heme. If blood is drawn for a medical test, the dark red color can be seen; however, if it is exposed to oxygen in the air, it will turn bright red like arterial blood.\n\nArterial blood is taken from any easily accessible artery (typically either radial, brachial or femoral) or out of an arterial line. The syringe is prepacked and contains a small amount of heparin, to prevent coagulation or needs to be heparinised, by drawing up a small amount of heparin and squirting it out again.\n\nOnce the sample is obtained, care should be taken to eliminate visible gas bubbles, as these bubbles can dissolve into the sample and cause inaccurate results. The sealed syringe is taken to a blood gas machine. If the sample cannot be immediately analyzed it should be chilled in an ice bath to slow metabolic processes that may also cause inaccuracy. The machine aspirates this blood from the syringe and measures the pH and the partial pressures of oxygen and carbon dioxide and the bicarbonate concentration, as well as the oxygen saturation of hemoglobin. Some machines can also measure glucose, lactate, hemoglobin and limited electrolytes (sodium and potassium).\n\nThe results are usually available within five minutes, and are now ready for interpretation.
228915
Lobster Blood is transparent or white, but because Copper is used to transport oxygen around their bodies (whereas humans use Iron), oxygenated blood is slighty blue.
1182716
The red respresents the blood shed in the stuggle for this nation.... the white represents the purity of the ideas that the founding fathers set forth and the blue represents the true faith and allegience that the sodliers and patriots had for the principles of freedom
909170
blue inside when air hits turns red?