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Current time:0:00Total duration:4:10

Video transcript

in this video we're going to talk about visual processing so how our brain is able to make sense of what we're looking at so in most of the our body we have the right side of the body being controlled by the left side of the brain and the left side of the body is controlled by the right side of the brain so how does this work envision so let's imagine that this rectangle that I drew is our entire visual field and if these two eyeballs were focused in at the center of this rectangle so if they were both focusing on this purple line all they can see are these two colors so we have a ray of light coming in from the left visual field it'll hit the eyeball it'll hit the left eyeball and it'll kind of be bent a little bit by the lens and it'll hit the right side of this eyeball and so the inner side of the eyeball so this side of this left eyeball and this side of the right eyeball is known as the nasal side because it's the nose would be right in the middle of the eyes so the nasal side is the side of the eyeball closest thin nose and then this outside part of the eyeball which is over here and over here is known as the temporal side of the eyeball because it's closest to your temple so this is the cyclist to the temples this is the Sai closer to the nose so a ray of light coming from the left visual field we'll hit the nasal side of the left eye and a ray of light coming from the left visual field will hit the right eye be bent a little bit by the lens and it'll hit the temporal side of the right eye so let's look at a ray of light coming from the right side of the visual field or ray of light coming from here would enter the right eye and it would be bent a little by the lens and hit the nasal side of the right eye whereas a ray of light coming in would hit the left eye be bent a little and hit the temporal side of the left eye so let's look at what happens next so the eye is basically connected to the brain via the optic nerve so there is an optic nerve that kind of exits the back of the eye and goes into the brain so interestingly the optic nerve from both eyes actually converge so they actually reach a point where they converge and this point right here where they converge is known as the optic chiasm so they kind of converge and then break off again and move even deeper into the brain so this point where they converge is known as the optic chiasm so optic chiasm let's look at how this information is transmitted to the brain through the optic chiasm the retinas lining the back of the eyeball and we had this yellow ray of light hit the nasal side of the left eye and it hit the temporal side at the right eye so let's go ahead and trace this information to the brain so the information will be sent via axons through the back of the eye into the optic nerve and basically it will come in and what it'll do is it'll actually cross at the optic chiasm and then go this way and what we also have is this ray of light will come in to the back of the eye and it will actually go down the optic nerve but it's not going to cross so all light that hits the temporal side of either eyeball does not cross the optic chiasm so let's go ahead and trace this green ray so the green ray coming from the temporal side of the left eye is going to exit the back of the eye go down the optic nerve and it's just going to stay in place so it's not going to cross the optic chiasm whereas this ray of light is going to go through the back of the eye and it's going to cross over here it's going to cross the optic chiasm and go down to the brain and so what this effectively does is it actually takes the right visual field and allows all the information that's entering the eye from the right visual field to go to the left side of the brain so this is the left side of the brain this is the right side of the brain so like the rest of the body all the information coming from the right visual field actually goes to the left side of the brain and all the information coming from the left visual field goes to the right side of the brain