The eyes of Leonardo da Vinci’s 
Mona Lisa appear to be looking 
at you whether you are in front 
or to the side of the picture.

    Understanding the nature of 
distortion or its absence in 
looking at pictures can help us 
explain some curious effects of 
picture perception. Perhaps the 
best known is the impression 
we have that the eyes in 
pictures of faces always seem to 
be looking at us no matter how 
far off to the side we stand. This 
is of course only true when the 
person in the picture has been 
painted or photographed as 
looking at the location of the 
painter’s eye or the lens of the 
camera, such as in the painting 
shown on the facing page. A 
person’s head may of course be 
variously positioned when 
looking at a photographer or 
painter. If the head is turned 
toward the camera or artist, the 
pupil would be centered with 
respect to the eye; if the head is 
turned away, the eyes would be