Goopy eyes and Car seat advice

I took Lani to our doctor yesterday and she does have conjunctivitis. I had no idea how that was possible since no one that she has been around has it. She said that Lani may have a virus that showed its self through her eyes or Wesley may have brought it home from school. I vote for the virus because I have Wesley wash his hands as soon as he walks in the door from school!
Now she is on Erythromycin cream and it seems to be working after only one application. I thought that she would scream but she really didn’t mind it.
They did weigh her at the appointment and she was exactly 18 pounds. The doctor also suggested that we start looking into another car-seat for Lani because she seems to be getting too tall for the infant seat! Now comes the adventure of finding the safest car-seat at the best value! Any of you have success with ones that can be rear facing for those under one? We did not have to get one for Wesley so I need to educate myself a little on this!