The contents of the Vision Reference Library and Davis Vision site, such as text, graphics, images, and other material contained on the site ("content") are for informational purposes only. The content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your qualified health provider with any questions you may have regarding a condition. Never disregard professional medical advice or delay in seeking it because of content on the Davis Vision site. Reliance on any Davis Vision site content is solely at your own risk. If you think you may have a medical emergency, call your doctor or 911 immediately.