‘Blind Side’ Actor Quinton Aaron on Life Support, Partially Breathing, Gives ‘Thumbs Up’

3:20 PM PT — Quinton Aaron‘s wife Margarita tells TMZ … “He opened his eyes today and gave a thumbs up.”

Quinton Aaron — the actor who played Michael Oher in “The Blind Side” — is on life support after being hospitalized following a collapse at his home … but there are some positive signs for his recovery.

Quinton’s wife, Margarita, tells TMZ … the medical devices helping keep Quinton alive aren’t doing all the work, and he’s partially breathing on his own, which gives the family hope.

We’re told Quinton’s been hospitalized for 4 days now … and with each passing day, he shows more signs of improvement.

Quinton’s wife says he has a blood infection and doctors are still running a battery of tests to determine the source of the issue.

Margarita tells us her husband woke up one morning feeling sore but thought it was from a bad sleep … a few days later, with pain still in his neck and his back, Quinton was walking up the stairs when he lost feeling in his legs.

Quinton’s wife, who is a registered nurse, says she rushed to his side and helped him up the stairs … he laid down, and she called 911 … with Quinton slipping in and out of consciousness on his way to the hospital, where doctors recommended life support.