During middle age, usually beginning in the 40s, people experience blurred vision at near points, such as when reading, sewing or working at the computer. There’s no getting around it; this happens to everyone at some point in life, even those who have never had a vision problem before.
Presbyopia Symptoms and Signs
When people develop Presbyopia, they find they need to hold books, magazines, newspapers, menus and other reading materials at arm’s length in order to focus properly. When they perform near work, such as handwriting, they may have headaches or eyestrain, or feel fatigued.

What Causes Presbyopia?
Presbyopia is caused by an age-related process. This is different from Astigmatism, nearsightedness, and farsightedness, which are related to the shape of the eyeball and caused by genetic factors, disease, or trauma. Presbyopia is generally believed to stem from a gradual loss of flexibility in the natural lens inside your eye.

These age-related changes occur within the proteins in the lens, making the lens harder and less elastic with the years. Age-related changes also take place in the muscle fibers surrounding the lens. With less elasticity, the eye has a harder time focusing up close.