/ˌɑːp.tɪ.kəl ɪˈluː.ʒən/ something that methods your eyes and would make you're thinking that you see a thing that is probably not there, or see it differently from how it truly is/ˌɑːp.tɪ.kəl ɪˈluː.ʒən/ something which tips your eyes and helps make you believe the thing is a thing that is probably not there, or see it in another