Abstract
In certain embodiments a light therapy system (e.g., phototherapy device), such as for treatment of Alzheimer's disease, depression, dementia, short-term memory, or for improved learning, improved athletic performance or improved cognitive performance, is provided where the light system comprises a blue light source that operates at a frequency in the range from 20 to 50 Hz (preferably around 40 Hz), whereby the system enables retinal ganglion cells of a human to be exposed in order to stimulate brain waves (gamma oscillations in the human's brain).