I have noticed while watching NFL games that on the quarterback's helmet there is a green dot. Can anyone tell me what that signifies and is the quarterback the only ones that have it on their helmet?

The dot lets the officials know which player is able to communicate with the sidelines via radio.

The green dot on the back of quarterback's helmets is a mark showing that they have the electronics in their helmet so that they can hear the play call from the sideline.

this has been answered many times here, but it means that the helmet has communication capabilities. The QBs have it so they can talk with the coach.

It is a focal point for unmanned aerial drones. The cia and the Air Force use those green dots to relay radio and communication transmissions to the drones that fly overhead.

Can you give me an answer to my questions?

1) Do you know how many times this question has been asked?

2) Do you know how to use search?

3) Do you know how tired we all are of that question?

Its a target for snipers, they are just waiting for the QB to quit moving long enough for them to get a good shot off.

....I am beginning to hate that ******* green dot!

The green dot signifies that the player is wearing a special helment that has communication with the coaches on the sideline. I believe only 1 player per team can wear this helmet on the field at any given time. This is used for giving the QB or defensive captain the play calls. Communication is cut-off with 10 to 15 left on the play clock. (There is no communication during the play, only inbetween plays)

Ahhh there it is now I can reset the abacus 364523 times!