clipped from: en.wikipedia.org   

1. No eye opening
2. Eye opening in response to pain. (Patient responds to pressure on the patient’s fingernail bed; if this does not elicit a response, supraorbital and sternal pressure or rub may be used.)
3. Eye opening to speech. (Not to be confused with an awaking of a sleeping person; such patients receive a score of 4, not 3.)
4. Eyes opening spontaneously