1 Qui-Gon Jinn: Always remember, your focus determines your reality.
2 Anakin: That sounds deep.
3 Qui-Gon Jinn: Yes, it is.
4 Qui-Gon Jinn: Unfortunately my eyesight is getting a little old, so my reality is increasingly blurry.

It's a human inevitability that our eyesight gets worse as we age. The lenses at the front of our eyeballs becomes less flexible over time, and around age 40-50 years we become unable to focus on nearby objects, such as reading material. This condition is known as presbyopia, and it affects everyone of the appropriate age to at least some degree. It's why older people commonly require reading glasses.

Except oddly it doesn't seem to affect anyone in the Star Wars universe. Except maybe Maz Kanata.