Below are brain SPECT imaging scans by Dr. Amen. SPECT measures blood flow and activity in the brain and shows areas with healthy activity, too much activity, and too little activity. On the left is an Irlen sufferer's brain scan prior to getting their Irlen lenses. You can see it is remarkably overactive, which is consistent with some types of anxiety, depression, and ADD/ADHD. In the second brain scan, taken while wearing Irlen lenses, the brain was significantly calmer and better able to process visual information.