I was always under the impression that August or September (basically RIGHT when they start reviewing your file) was early and that January or later was late. The deadline is in February for some schools e.g., SUNY (Feb 15). Since most optometry schools are on rolling admissions, it would be best to get it in at the start of the cycle. SUNY actually begins accepting applications as early as May the year before enrollment. You can even send your application in before the school officially takes them in August; they will just take your application and set it aside to be reviewed once the cycle begins (at least that's what Todd Eicker at PCO told our pre-opt club).
I'm going to assume that you are applying for 2007 enrollment and that it doesn't help for me to say that half a year ago is when you should have applied. I'm just going to say that I'd be a lot happier if I could just follow my own advice and that you're not alone. If anything, we're both in the "on time" period of applications so good luck to you and get them in!