The statement that people have eyes in the back of their head may have a little truth to it. In the brain, the occipital lobe is located in the back of the head. It is actually two lobes, with a right and left side corresponding to right/left brain hemispheres. This area is responsible for controlling most vision and visual processing. Thus, while a person may not see out the back of his or her head, they see from it and this area of the brain interprets the images taken in by the eyes.
The occipital lobe is located behind the parietal lobe, and it sits on top of the membrane that separates it from the cerebellum, which is below it. As mentioned, its function tends to be most associated with vision. Not only does it allows us to see and identify objects, but it also does things like see colors and interpret that each color is different. Occipital function is involved early in life as infants begin to see. As children receive visual stimuli, it gets sent to this region and is ultimately interpreted. More acute vision and ability to understand images occurs as children grow.
The work of the occipital lobe not only helps with visual recognition but can also help understand and differentiate between shapes. Things like basic geometric understanding of shapes would be impossible without this brain area. The brain would lack the capacity to distinguish between objects like circle/square or triangle/pentagon. Moreover, trying to interpret an alphabet, could be challenging with this processing section, since differences in letters often come down to slight changes in shape.
It is certainly no surprise that damage, lesions, or any illness affecting the occipital lobe may be very severe and alter vision. One condition, called occipital lobe epilepsy originates in this part of the brain. It results in unusual seizures that are characterized by hallucinations, sometimes seeing an image again and again, and repeated blinking of the eyes or uncontrolled eye movements. While a seizure is progressing, blindness can occur and some people note exceptional eye pain as well. Though this condition may represent dysfunction of the occipital lobes, it can very fortunately respond to treatment with medication.
Others times occipital lobe damage is not as reparable and people with such damage could suffer frequent visual hallucinations or fail to interpret any visual information they take in. This could in turn lead to errors in perception, faults in vision or sometimes complete vision dysfunction. Temporary or permanent injuries to the back of the brain might suggest involvement of the occipital lobe if they result in vision changes or blindness.
