C25,P21Only need to answer question 21. Question 20 is needed to answer question 21. | 20. • Contact lenses. Contact lenses are placed right on the eye-BIO ball, so the distance from the eye to an object (or image) is thesame as the distance from the lens to that object (or image). Acertain person can see distant objects well, but his near point is45.0 cm from his eyes instead of the usual 25.0 cm. (a) Is thisperson nearsighted or farsighted? (b) What type of lens (con-verging or diverging) is needed to correct his vision? (c) If thecorrecting lenses will be contact lenses, what focal length lensis needed and what is its power in diopters?| 21. ●• Ordinary glasses. Ordinary glasses are worn in front ofBIO the eye and usually 2.0 cm in front of the eyeball. Suppose thatthe person in the previous problem prefers ordinary glasses tocontact lenses. What focal length lenses are needed to correcthis vision, and what is their power in diopters?

near point = 45 cm least distance of distinct vision = 25 cm distance between eye and glasses = 2 cm…

| 21. . Ordinary glasses. Ordinary glasses are worn in front of BIO the eye and usually 2.0 cm in front of the eyeball. Suppose that the person in the previous problem prefers ordinary glasses to contact lenses. What focal length lenses are needed to correct his vision, and what is their power in diopters?

| 21. . Ordinary glasses. Ordinary glasses are worn in front of BIO the eye and usually 2.0 cm in front of the eyeball. Suppose that the person in the previous problem prefers ordinary glasses to contact lenses. What focal length lenses are needed to correct his vision, and what is their power in diopters?

College Physics

10th Edition

ISBN:9781285737027

Author:Raymond A. Serway, Chris Vuille

Publisher:Raymond A. Serway, Chris Vuille

Chapter25: Optical Instruments

Section: Chapter Questions

Problem 65AP: A cataract-impaired lens in an eye may be surgically removed and replaced by a manufactured lens....

See similar textbooks

Similar questions

During LASIK eye surgery (laser-assisted in situ keratomileusis), the shape of the cornea is modified by vaporizing some of its material. If the surgery is performed to correct for nearsightedness, how does the cornea need to be reshaped?
A cataract-impaired lens in an eye may be surgically removed and replaced by a manufactured lens. The focal length required for the new lens is determined by the lens-lo-retina distance, which is measured by a sonar-like device, and by the requirement that the implant provide for correct distance vision. (a) If the distance from lens to retina is 22.4 mm, calculate the power of the implanted lens in diopters. (b) Since there is no accommodation and the implant allows for correct distance vision, a corrective lens for close work or reading must be used. Assume a reading distance of 33.0 cm, and calculate the power of the lens in the reading glasses.
Can an image be larger than the object even though its magnification is negative? Explain.
Example 23-9 : Image formed by a converging lens. What are (a) the position, and (b) the size, of the image of a 7.6-cm-high leaf placed 1.00 m from a +50.0-mm-focal-length camera lens?
What is the focal length of a makeup mirror that produces a magnification of 1.50 when a person’s face is 12.0 cm away? Explicitly show how you follow the steps in the ProblemSolving Strategy for Mirrors.
If the cornea is to be reshaped (this can be done surgically or with contact lenses) to correct myopia, should its curvature be made greater or smaller? Explain. Also explain how hyperopia can be corrected.
Can a case 1 image be larger than the object even though its magnification is always negative? Explain.
(a) What is the focal length of a magnifying glass that produces a magnification of 3.00 when held 5.00 cm from an object such as a rare coin? (b) Calculate the power of the magnifier in diopters. (c) Discuss how this power compares to those for store-bought reading glasses (typically 1.0 to 4.0 D). Is the magnifier's power greater, and should it be?
Why is your vision so blurry when you open your eyes while swimming under water? How does a face mask enable clear vision?
In a LASIK vision correction, the power of a patient’s eye is increased by 3.00 D. Assuming this produces normal close vision, what was the patient’s near point before the procedure?
Some telephoto cameras use a mirror rather than a lens. What radius of curvature mirror is needed to replace a 800 mm focal length telephoto lens?
Suppose a certain person’s visual acuity is such that he can see objects clearly that term an image 4.00 m high on his retina. What is the maximum distance at which he can read the 75.0 cm high letters on the side of an airplane?