Ford produced Model Ts in this manner for three years at its new Highland Park plant before adopting the assembly line. When modern drivers think about the Ford Model Tâif they think about it at allâthey perhaps dimly perceive it as the car that changed the world.
The Cornea. The cornea represents the strongest part of the refracting power of the eye, providing about 80% of the power of the system. The index of refraction of the cornea is about 1.376. Rays pass from the cornea into the watery fluid known as the aqueous humor which has an index of refraction of about 1.336, so most of the refraction is at the cornea-air interface.
The retina is a multi-layered sensory tissue that lines the back of the eye. It is approximately 0.5mm thick, and consists of an outer pigmented layer of specialised epithelial cells and an inner neural portion. The middle of the retina is called the macula, and the centre of the macula contains the fovea. The fovea is specialised for detailed vision, and is naturally directed at objects when we look at them. The outer retinal pigment epithelium is a single layer of cells that abuts the underlying choroid.