From Alan Kelly
Visual illusions may be more than a by-product of efforts to “make sense of partial visual details” as you quote Susana Martinez-Conde saying (18 September, p 38).It may be that our brains actively seek differing interpretations of the same image. It would surely be an advantageous trait for any prey species whose foe had a tendency towards camouflage, or operated in poorly lit conditions.
Castlerea, County Roscommon, Ireland
