Ch24,P24 |24. . Focus of the eye. The cornea of the eye has a radius ofBIO curvature of approximately 0.50 cm, and the aqueous humor behind it has an index of refraction of 1.35. The thickness ofthe cornea itself is small enough that we shall neglect it. Thedepth of a typical human eye is around 25 mm. (a) What wouldhave to be the radius of curvature of the cornea so that it alonewould focus the image of a distant mountain on the retina,which is at the back of the eye opposite the cornea? (b) If thecornea focused the mountain correctly on the retina asdescribed in part (a), would it also focus the text from a com-puter screen on the retina if that screen were 25 cm in front ofthe eye? If not, where would it focus that text, in front of orbehind the retina? (c) Given that the cornea has a radius of cur-vature of about 5.0 mm, where does it actually focus themountain? Is this in front of or behind the retina? Does thishelp you see why the eye needs help froma lens to completethe task of focusing?

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behind it has an index of refraction of 1.35. The thickness of the cornea itself is small enough that we shall neglect it. The depth of a typical human eye is around 25 mm. (a) What would have to be the radius of curvature of the cornea so that it alone would focus the image of a distant mountain on the retina, which is at the back of the eye opposite the cornea? (b) If the comea focused the mountain correctly on the retina as described in part (a), would it also focus the text from a com- puter screen on the retina if that screen were 25 cm in front of the eye? If not, where would it focus that text, in front of or behind the retina? (c) Given that the cornea has a radius of cur- vature of about 5.0 mm, where does it actually focus the mountain? Is this in front of or behind the retina? Does this help you see why the eye needs help froma lens to complete the task of focusing?

behind it has an index of refraction of 1.35. The thickness of the cornea itself is small enough that we shall neglect it. The depth of a typical human eye is around 25 mm. (a) What would have to be the radius of curvature of the cornea so that it alone would focus the image of a distant mountain on the retina, which is at the back of the eye opposite the cornea? (b) If the comea focused the mountain correctly on the retina as described in part (a), would it also focus the text from a com- puter screen on the retina if that screen were 25 cm in front of the eye? If not, where would it focus that text, in front of or behind the retina? (c) Given that the cornea has a radius of cur- vature of about 5.0 mm, where does it actually focus the mountain? Is this in front of or behind the retina? Does this help you see why the eye needs help froma lens to complete the task of focusing?

University Physics Volume 3

17th Edition

ISBN:9781938168185

Author:William Moebs, Jeff Sanny

Publisher:William Moebs, Jeff Sanny

Chapter2: Geometric Optics And Image Formation

Section: Chapter Questions

Problem 22CQ: If the cornea is to be reshaped (this can be done surgically or with contact lenses) to correct...

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