Eyestrain

Anyone who reads for hours works at a computer or drives long distances knows about this one. It happens when you overuse your eyes.

Lazy Eye

Vision is weaker in that eye, and it tends to move “lazily” around while the other eye stays put.

Presbyopia

After age 40 or so, you may have to hold a book or other reading material farther away from your eyes to make it easier to read. Sort of like your arms is too short.

Excess Tearing

 Try to protect your eyes by shielding them or wearing sunglasses (go for wraparound frames -- they block more wind than other types).