Please choose the correct ending to complete the given sentence: Health: [header] How to adjust eye glasses [title] Stand in front of a mirror and look straight ahead. [step] Position the eyeglasses so the middle of the lenses are located in the center of your eyes. This is the optical center and the ideal location for your eyeglasses.

Ending1: [title] Find the correct " point of focus. [step] " the point of focus over your eyes should be the center of the bridge of your nose. Ending2: All adjustments to your eyeglasses should be made to achieve this optimal position. [substeps] If you have a bifocal lenses, the line should sit at the lower eyelid. Ending3: Try situating them so the other side is facing you. [title] Adjust the upper and lower lenses as necessary. Ending4: Position the glasses so that they face the light source. [substeps] As you stand, you should be holding them perfectly still.

Answer format: ending1/ending2/ending3/ending4