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Foveal Acuity

Foveal Acuity. Ellen Thomson Casey Laudenbach Megan Gebhardt Hanna Honn Dinglan Tang Maria Stevens. What is Foveal acuity?. A measure of the finest detail that can be resolved by the eyes

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Foveal Acuity

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  1. Foveal Acuity Ellen Thomson Casey Laudenbach Megan Gebhardt Hanna Honn Dinglan Tang Maria Stevens

  2. What is Foveal acuity? • A measure of the finest detail that can be resolved by the eyes • Recall that the fovea is the area of the eye that contains the highest concentrations of cones (but no rods). This area results in the highest visual acuity • You experience the most clarity, sharpness, and detail when you are looking right at something

  3. Defining Acuity • Herman Snellen’s formula for defining acuity: • (distance at which a person can just identify the letters) ______________________________________________ (distance at which a person with “normal” vision can just identify the letter) To put this into context: A “20/40” acuity means that you have to be 20 feet away to read a letter that a normal person could decipher at 40 feet. This means that you see worse than a normal person.

  4. VIdeo • http://v.youku.com/v_show/id_XMzYwMDg0NTk2.html

  5. Periphery Vs Fovea • Low resolution when not in center gaze. • No rods, just cones in the fovea. • In the fovea, the retinal ganglion cells have smaller receptive fields, and in the periphery, they have much larger receptive fields. • We have 125 million rods and 6 million cones.

  6. Light activity Demonstrating the changes in foveal acuity in average lighting and then with minimal lighting.

  7. Website activity http://sites.sinauer.com/wolfe3e/chap3/foveaF.htm • Lets test your foveal acuity!!!

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