MODULE: Anatomy of the eye
Step 06 of 07: Environmental factors
Our experiences of this size and distance relationship result in some notable anomalies in visual perception of simple geometric shapes and the proportions of the printed page, where we are still applying our expectations of the physical world. The classic example here is the MULLER-LYER illusion below where, due to the different arrow heads, the vertical lines are perceived to be different heights despite being the same;
though perceived differently according to culture (SEGALL, CAMPBELL & HERSKOVITS, 1966)
Interestingly though this illusion is not interpreted the same across all cultures. In 1966, SEGALL, CAMPBELL & HERSKOVITS found that members of a Zulu tribe did not identify any difference in the two compositions. It has been posited that the effect is strongest among western audiences as the left arrow can be unconsciously perceived as the outside of a building and the right, the inside of a room. With the inside of a room being logically closer than the outside of the nearest building, the right-hand-site arrow is judged to be larger.