Exercise 23 - Vision Lab

to act as a window to the eye and helps focus entering light rays

to form the bulk of the fibrous layer, to provide protection and serves as an attachment for the extrinsic muscles

to act to bend the rays of light so that they are properly focused on the rear of the eye

to help regulate the amount of light entering the eye

to change size to adjust for the amount of light available (smaller for bright light and larger for low light)

to fill the space between the cornea and lens, helps to nourish these parts, and aids in maintaining the shape of the front of the eye

to fill the posterior cavity, and together with some collagenous fibers, comprises the vitreous body, supports the internal parts of the eye and helps maintain its shape

to carry visual information from the eye to the brain

to act as an entry point for the main blood vessels that supply blood to the retina

receives light focused from the lens, converts the light into neural signals, send these signals on to the brain, and processes light through a layer of photoreceptor cells

is responsible for sharp central vision, which is necessary for reading, watching t.v or movies, driving and any activity where visual detail is of primary importance

to absorb scattered light to increase resolution, aids in recycling photopigments by storing vitamin A, and phagocytosis of older receptor segments and pathogens

• Action - move eye laterally
• Controlling cranial nerve - VI (abducens)

• Action: move eye medially
• Controlling cranial nerve - III (oculomotor)

• Action: elevates eye and turns it medially
• Controlling cranial nerve: III (oculomotor)

• Action: depresses eye and turns it medially
• Controlling cranial nerve: III (oculomotor)

• Action: elevates eye and turns it laterally
• Controlling cranial eye nerve: III (oculomotor)

• Action: depresses eye and turn it laterally
• Controlling cranial nerve: IV (trochlear)