Yeah, subtle visions on the corner of your eye that aren't actually there, tracers, brighter colours, etc... all that's fairly common for me after taking a significant dose of MDMA.
Although... I remember a couple of years ago, a good mate of mine had a heapload of MDMA powder (over the 500mg mark), a few pills, some powdered Amphetamine Sulphate (as far as I know it was...), some Meth and some coke throughout the course of a big night and then he just suddenly flipped out in the club. Kept running and running, non-stop. We chased him to no luck. He kept on mumbling shit we couldn't comprehend and after that incident we didn't see, nor hear from him for about 5-6 days after that.
When we finally did catch up with him, it turns out he obviously took too many stimulants and "wigged out". We asked him where the hell he disappeared to and he told us he just caught a cab to Sheparton (we were in Melbourne CBD at the time, and he lives in South Yarra).
Apparantly he just needed some time to himself. I dunno.
So in-short, yes... it is most definately possible to hallucinate on MDMA in large doses, depending on individual and current mindset, I'd say it would be possible to hallucinate off even a particular small dose of MDMA.