The eye has a complex and exquisitely designed optical system yet, when compared with modern optical systems, its image quality is surprisingly poor. This course will discuss the optical properties of the different components of the eye from the cornea to the retina, and how they impact visual quality. We will evaluate benefits and limitations of various techniques, such as adaptive optics and laser refractive surgery, which have been developed to overcome the eye's optical limitations. Aberration limits will be presented so that designers of optical systems, where the eye often plays an intrinsic role, can estimate the degree of correction required for their products to produce high quality perceived imagery.