that's where I have the highest concentration of comas if every dot that I make represents an individual cone there's no gaps between the cones that means I don't miss anything I see the greatest amount of detail there as I go further out from the fovea the cones are spread out a little bit more and the further out I go the more spread out the cones become and when I get all the way out here to the edge they're fewer and further between fewer and further between so when we describe the fovea we describe it this way there's a location on the retina in the center of our visual field that has the highest that's my abbreviation for highest and up arrow with s highest concentration photoreceptors and it's comes only and that is where we have our Sun miss division you can do this quick experiment with me if you take your two pinkies and hold them up and you're staring at your fingerprints that put them at a distance where you can read your finger prints leave your left pinky there and stare at it and move your right pinky over some distance the left pinky you'll see every detail the right pinky will be blurry and missing information and the reason is your left pinky all of the photons are landing right here and we're not missing a single point of light but the other pinky which might be here would be coming in at an angle and some of those photons would be missing photoreceptors because the photoreceptors are spread out so we can't see those photons of light we're missing detailed in our peripheral vision that's why when we want to see the greatest amount of detail we turn our head and look at something if you hear a loud noise you turn and look at it so that you can identify exactly what it is so that's what the fovea is it's a spot on the retina in the center of our visual field that has the highest concentration of photoreceptors and cones only it's where we see the greatest amount of detail that's why we turn our eyes toward an object to see the detail turns out the rods are actually in Reverse there are no rods in the fovea the rods are at a higher concentration out in the periphery and the closer we get to the center of the eye if you learn further between the rods become that's why in the dark our peripheral vision is better than our central vision that's why we can see images and outlines but we can't see detail all right so anyway a couple of things I want you to know about this the fovea is where we have cones only we see the greatest detail if I were to destroy the fovea by the way you would not go blind and you would not lose the ability to see color because I still have combs in the eye but I would lose the ability to see great detail so in macular degeneration where the fovea and the macula are dying patients lose the ability to see great detail and blindness starts setting in they can still see color they can still see some but the loss of sharp vision occurs so now I hope that helps you understand sort of how the retina is set up what retinal organization is and the major functions of the retina how photoreceptors are set up in the retina and all of that anyway I believe that covers all the visual physiology that I want to cover there are some sections in your lecture textbook so I flipped through the note set I'm not going to do all the page 17 you can do the steps of visual physiology if you like you should also read about stereo vision you should read about day and night vision you should read all the details in the lecture text but the test questions that I'm going to cover are going to come from the lectures that I've done up to now so we're done with vision I hope you learned something I hope you had as much fun as I did now to see you in the next few lectures where we're going to cover equilibrium and hearing thanks for watching