It is all too easy to take healthy eyes for granted. People without vision problems forget that eye health and 20/20 vision are two different things. For those who wear corrective lenses, a yearly exam to check for prescription changes is a must to ensure optimal vision. But what if somebody can see just fine?Is a yearly exam necessary?Eye doctors vary in their recommendations for how often a person without vision problems should have an exam. Suggestions range from yearly to every two to three years, depending on a number of factors. People under age 40 with no family history of eye disease should have a comprehensive eye exam every two to three years. However, if any unusual symptoms develop, such as redness or irritation, blurry vision or headaches, they should schedule a checkup immediately to rule out the possibility of a serious problem.Clear vision is not necessarily an indication of perfect eye health. People who do not need glasses can still develop potentially serious eye conditions that only a medical exam can diagnose. Age mattersAfter the age of 40, eyes become subject to age-related problems. Most people need reading glasses starting sometime after age 40. Risk increases for cataracts, Diabetes-related eye problems, glaucoma and other serious conditions, and a yearly exam helps ensure that any developing issues are detected and treated in a timely manner. If there is a family history of any of these conditions, a yearly screening is especially important.Optometrist or opthamologist?Optometrists are trained to administer complete eye health and vision exams. If a serious medical condition is detected, they typically refer patients to an opthamologist for further diagnosis and treatment. An opthamologist is a medical doctor, and patients with high risk factors (advanced age, family history of eye disease, diabetes, etc) may prefer to make an opthamologist their primary care eye doctor.The best advice for how often to have an eye exam should come from a trusted eye care specialist. Patients should schedule a comprehensive vision and eye health screening with their physician or opthamologist and let him or her recommend how often a return visit is needed, based on age, health, family history and exam results.