Lecture Notes
March 26, 2013 Lecture
-The function of the eye is to convert photons of light into action potentials (nerve impulses).
-The inner layer is a nervous tunic (made out of nerve cells)=retina.
-Refraction: Bends light.
-The purpose of the cornea and the lens is to take an object and focus every little detail of the object on the retina on the back of the lens. Upside down and backwards.
-When light goes through medias, it bends.
-Lens are suspended by ligaments behind the pupil. Suspensory ligaments.
-Aqueous humor, vitreous, intraocular pressure. Liquid that creates internal pressure much like air in a basketball. Excess amount of intraocular pressure=glaucoma.
-The natural thermodynamically stable configuration or shape of a lens is more round like a marble (SPHERICAL).
-Why is an eye ball flat? The ligaments. The intraocular pressure stretches the lens flat? Flat is good for distance vision. Round is good for close vision.
-Ciliary muscle. When it contracts it will squeeze the eyeball smaller so it loosens the ligaments. Contract the muscle will make the lens round.
-The eye muscles are relaxing when viewing far away.
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Photon: unit of light.
-Want to take the photons of light and convert them to nerve impulses.
-Converting a photon of light into nerve impulse: transduction.
Two kinds of photoreceptors: receive photons of light.
Rods: Can only see in very very dim light. It is too bright in room for them to function. They bleach out outside in sunlight. They are excellent in dim light like at the dead of night.
Cones: Unlike rods. They can see in detail and color.
Photoreceptors cells synapse with a bi-polar cell which synapses with a ganglion cell. The axons of ganglion cells emerge from the eye all packed together to make up the optic nerve. The optic nerve will carry nerve impulses to the brain. Light hits the photoreceptor.
Direct pathway from photoreceptor to ganglion
-The function of the eye is to convert photons of light into action potentials (nerve impulses).
-The inner layer is a nervous tunic (made out of nerve cells)=retina.
-Refraction: Bends light.
-The purpose of the cornea and the lens is to take an object and focus every little detail of the object on the retina on the back of the lens. Upside down and backwards.
-When light goes through medias, it bends.
-Lens are suspended by ligaments behind the pupil. Suspensory ligaments.
-Aqueous humor, vitreous, intraocular pressure. Liquid that creates internal pressure much like air in a basketball. Excess amount of intraocular pressure=glaucoma.
-The natural thermodynamically stable configuration or shape of a lens is more round like a marble (SPHERICAL).
-Why is an eye ball flat? The ligaments. The intraocular pressure stretches the lens flat? Flat is good for distance vision. Round is good for close vision.
-Ciliary muscle. When it contracts it will squeeze the eyeball smaller so it loosens the ligaments. Contract the muscle will make the lens round.
-The eye muscles are relaxing when viewing far away.
-------------------------------------------------
Photon: unit of light.
-Want to take the photons of light and convert them to nerve impulses.
-Converting a photon of light into nerve impulse: transduction.
Two kinds of photoreceptors: receive photons of light.
Rods: Can only see in very very dim light. It is too bright in room for them to function. They bleach out outside in sunlight. They are excellent in dim light like at the dead of night.
Cones: Unlike rods. They can see in detail and color.
Photoreceptors cells synapse with a bi-polar cell which synapses with a ganglion cell. The axons of ganglion cells emerge from the eye all packed together to make up the optic nerve. The optic nerve will carry nerve impulses to the brain. Light hits the photoreceptor.
Direct pathway from photoreceptor to ganglion