"It is very disappointing when you are 2-0 up against 10 men and end up drawing the game," said Grayson.
"It seems like a defeat in the dressing room. But you have to take the positives out of it. Because for 30 minutes in the first half I felt we were outstanding. We passed the ball really well, created chances and could have been well clear.
"The big defining moment was probably when their keeper made a fantastic double save and tipped it onto the post. But you have got to give credit to Orient.
"They had a real go at us. They galvanised the crowd because we were totally in control. Obviously we are disappointed with the result but we still have to remember we have taken four points away from home from the past two games and we have won seven and drawn three of the last 10."