Page 42 - Mind Games The Aging Brain and How to Keep it Healthy

26 • Chapter 2

LEFT VISUAL FIELD RIGHT VISUAL FIELD

Temporal Nasal Nasal Temporal

Left eye Right eye

Optic nerve
Frontal lobe

Optic chiasm Temporal
lobe
Optic tract

Optic
radiation

Occipital lobe

Visual cortex

Figure 2-2 Pathway from retina to visual cortex

At birth, the brain weighs approximately three-quarters
of a pound. The migrating axons have reached the correct
general area but not necessarily the exact site. The neurons
in the visual cortex alone form about 2,500 connections per