Some eye diseases cause symptoms that alert you that something is wrong— symptoms such as blurred vision, eye pain, red eyes, floaters, or flashing lights. Unfortunately, there are also serious, vision-threatening problems that have no warning signs. Proper eye care and medical evaluation of your eyes can help avoid preventable loss of vision in many of these cases. Because a thorough eye examination also allows your doctor to directly view your blood vessels (vessels may be seen in the retina as noted in the picture above), annual eye exams can also help detect diabetes, hypertension, and other important treatable medical conditions.