They do apply a subjective sharpening (literally like an image processing sharpen filter) to the entire field of vision, and they also enhance pattern recogniti

They do apply a subjective sharpening (literally like an image processing sharpen filter) to the entire field of vision, and they also enhance pattern recognition, and so details that might be more difficult to see stand out. But on the other hand, they also make it more difficult to concentrate, and they also make you see patterns that don't actually exist. So it's difficult for me to imagine anyone using them for immediately practical purposes successfully.