The definition of a vital organ is part of a human component which is needed in order for the person to survive. The larynx is basically the voice box, that's why you see people who can't talk still living :)
You use the nervous system. Your brain is the main organ of the nervous system or it is known as the control center of the nervous system.
there is no evidence that the human eye is an organ as we need organs to survive, if we didnt have an organ, we would eventually die, but people can live without eyes.
Appendix
If you are discussing live organ donation, such as part of the liver or a kidney, and you are medically expected to need such a donation at some point, then yes your friend can be tested for matching to you prior to the need for a donated organ.
Eyes
No, the eyes are the only organ that can see. Actually, blind people use their feeling (hands), hearing (ears) and smelling (nose) to see things as it creates a virtual image in their mind therefore seeing where things are.
the organ is the loin.
On avergage how many people in the United States will need an organ transplant? On average how many people in the world will need a organ transplant? Why is selling a organ illegal?
The heart is one organ associated with the circulatory system.
eye
The organ in the body that lets you see is the eye. This is controlled by the optical nerves which are found in the brain.
They use a microscope
A vestigial organ is one having no known use.
I just love the sound of a pipe organ.
The definition of a vital organ is part of a human component which is needed in order for the person to survive. The larynx is basically the voice box, that's why you see people who can't talk still living :)
Integumentary system