Vision - The most common vision problems are refractive errors, more commonly known as nearsightedness, farsightedness, astigmatism and presbyopia. Refractive errors occur when the shape of the eye prevents light from focusing directly on the retina. An eye care professional can diagnose refractive errors during a comprehensive eye examination. Many visit their eye care professional with complaints of discomfort or blurred vision, but others don’t know they aren’t seeing as clearly as they could. Even if you have no signs, regular eye exams are recommended—especially for those with some chronic health conditions such as diabetes and high blood pressure. Early detection and treatment can be the key to preventing sight loss.