Light waves striking the rods and cones bring about chemical changes that generate neural signals. ... Light enters the eye through the cornea, a transport protector; it's the clear bulging surface in front of the eye, and the main refractive surface of the eye. ... The iris is highly pigmented and has a remarkable ability to adjust light intake by dilating and constricting in response to light intensity and even to inner emotions. Behind the pupil is a lens that focuses the incoming rays into an image on the light sensitive back surface. ... Nearsighted vision is when the light rays f...

• Word Count: 780
• Approx Pages: 3
• Grade Level: High School

An excimer laser applies waves of ultraviolet light to reshape the corneal tissue of the eye to match the prescription from the patient's glasses or contact lenses (Spectera). ... The benefits of having LASIK laser eye surgery compared to PRK (Photo Refractive Keratectomy) are that the corneal tissue is not removed thus allowing post surgery corrections easier to perform. ... Side effects including discomfort, blurry vision, scratchiness, dryness, glare, haloes around lights, light sensitivity, and red patches on the white of the eye may result from surgery. ...

• Word Count: 603
• Approx Pages: 2
• Grade Level: Undergraduate