The simple answer is...oh yes you do! Being the good researcher you are though, you probably want to know why.
Although patients judge the health of their eyes and the quality of our work by their vision, it only tells part of the story. We actually look at many more things during a yearly eye exam, much of it with little discussion if everything is normal, which it most often is. The problem is, abnormal conditions are not rare and frequently do not have symptoms. Two examples are glaucoma and ocular melanoma.
Glaucoma is actually quite common. One in twenty patients age 50 have it...one in five who are 80. Once a patient has symptoms, they are actually on the precipice of total blindness. It's FAR better to catch it during the phase where it is asymptomatic.
Although much less common, ocular melanoma, a cancerous tumor in the eye, not only can rob a patient of their vision, but take their life!
These conditions are just two of MANY diseases that we screen for during an otherwise routine yearly exam.
So, the answer still stands. Even if you see just fine, and don't wear glasses or contact lenses, it's important to see an eye doctor yearly, especially those of you over 40.