Your vision is one of the first senses to be effected by age.
Your ability to see up close diminishes starting at the age of 40. This condition is called Presbyopia and continues to worsen with age.
The risk of Cataracts, Glaucoma, Macular Degeneration, and other eye diseases also increases with age. Many of these conditions can be treated or slowed down if detected early. It is therefore very important to have regular eye exams as you age.