Visualization exercise
How to make comparisons with your eyes closed
Place anything before you. First, choose any simple object preferably with a non-reflective surface (toys will do nicely). If this is not possible, make your task simpler by singling out some small object, say, a mobile phone. On the one hand, this is a rather complex object, on the other, you can focus on one simple detail only, for instance, a button.
Take a sitting position. Relax. Focus on the object. Look at for several minutes, trying to memorize the tiniest details. Look at the center, trying to see the entire object, thus developing your peripheral vision. To avoid unwanted thoughts, you should prevent your eyes from roving about the room. Now close your eyes. Try to keep the object in your mental view as long as possible. Do this 3-5 times a day in one position at a time. Change an object immediately if you get bored with it. You can repeat the exercise more than five times if you get pleasure from it.