Presbyopia is the gradual decline of your eyes’ ability to focus on nearby objects, causing the objects to appear blurry and out of focus. If you’ve noticed you have to hold a book farther away to read than you used to, you may be experiencing presbyopia.
Nearly everyone experiences presbyopia by their mid-40s. Much like adjusting the focus on a camera, a healthy eye lens flexes and changes shape to properly focus on objects at different distances. But as your eyes age, they lose their ability to flex. The result is diminished up-close vision. Thankfully, there are many different ways to treat presbyopia.
source: myeyes.com by Alcon