Valverde's side generally controlled proceedings in France, but they were wasteful in front of goal and Lionel Messi was unable to create much of note.
It leaves the tie nicely poised for the second leg at Camp Nou on March 13 and Barca will be seen as favourites, but Valverde is well aware that Tuesday's result provides Lyon with encouragement.
"I do not think it is very easy to win away from home in the Champions League," Valverde told Movistar . "We have absolutely dominated and they have not lost any match in this competition so far this season.
"Lyon had chances in the beginning but we came back well and we controlled the game until the end.
"We have created a lot of chances, but football is a matter of success and today we have not had it. The tie is in the air, 0-0 is a dangerous result, we will not kid ourselves."
Lyon defender Leo Dubois believes the draw gives his side every chance to progress to the quarter-finals and feels they did well despite Messi occupying more than one defender at a time.
"They have a player [Messi] who keeps a full defensive line busy," he said. "We tried to push them out from the middle, as they are less of a threat from the wings.
"The scoreline is fine for us. We still have a chance to progress even if we know it will be tough. We believe in ourselves.
"We weren't necessarily in control at times. We may also have mismanaged some counter situations. Everyone did their part and made the effort. We have everything to play for in three weeks. It's up to us to play a big match."