Test method: 1, about 1.5 meters from the screen, parallel viewing. 2, if the person being tested wears glasses or contact lenses, the test does not need to take them off, can be tested directly. 3, the test subject first gently cover the left eye with his or her hand (do not need to stick or press the eye), while both eyes should be open. 4. The tester starts with a large figure and asks the tester to point out the direction of the opening of the figure. If correct, then slowly test to the smallest figure. 5. After the right eye test, do the same for the left eye. If the direction of the opening of any of the figures cannot be confirmed or is difficult to identify, please go to a professional eye medical department for a detailed examination as soon as possible.