Eye Diseases and Conditions Slideshow Pictures Pink Eye Slideshow Pictures Laser Eye Surgery Pictures Cornea: The clear front window of the eye, which transmits and focuses light into the eye. The cornea is more than a protective film; it is a fairly complex structure that has five layers. From Eye Health Resources How's Your Eye Health?Diabetes and Your EyesEye Care for Diabetes Featured Centers When Prostate Cancer SpreadsEssential Tips to Manage DiabetesWhat Is Cystic Fibrosis? What Causes It? Health Solutions From Our Sponsors Kept Your Wisdom Teeth? What is TAVR?