What is the difference between a coma and a vegetative state?

Awake versus not : A coma is a state of unconsciousness. A person in coma does not open eyes, or respond to the environment beyond reflexes. In vegetative state there may be eye opening, and even the patient may follow objects with their eyes, yawn and appear more "awake" but do not speak, follow commands or move purposefully. Both involve significant brain disorder. Prognosis can vary based on cause, .