Help with optics problem involving diopters

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Homework Help Overview

The problem involves determining the correct eyeglasses prescription for a nearsighted individual who currently uses contact lenses with a refractive power of -3.60 diopters. The context includes the distance at which the eyeglasses will be worn from the eyes, specifically 2.30 cm.

Discussion Character

  • Mixed

Approaches and Questions Raised

  • Participants discuss the relationship between the refractive power of contact lenses and the eyeglasses prescription, with some questioning the relevance of the contact lenses' power. There are attempts to apply the mirror equation and conversions related to focal lengths. One participant reflects on a calculation error regarding the distance adjustment.

Discussion Status

The discussion includes various interpretations of the problem setup and calculations. Some participants have provided insights into their reasoning, while others have expressed confusion about the methods used. There is no explicit consensus on the correct approach, but some productive direction has emerged regarding the calculations.

Contextual Notes

Participants are working under the assumption that the contact lenses provide perfect vision at infinity, which raises questions about the relevance of their refractive power in determining the eyeglasses prescription. There are also indications of misinterpretation of the problem details by at least one participant.

Altagyam
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Homework Statement


A nearsighted man uses his ideally prescribed contact lenses that have a refractive power of −3.60 diopters. He would like a prescription for eyeglasses. What is the correct eyeglasses prescription if he wears his eyeglasses a distance of 2.30 cm from his eyes?

Homework Equations


I used the mirror equation. 1/f = 1/do + 1/di

The Attempt at a Solution


I found a solution to be -3.32 and what I did was convert the refraction power to focus and then convert it to centimeters and added 2.3 and then did the inverse of that to obtain -3.32 and apparently that is wrong. I have used chegg and they show the same exact method I employed. I don't understand. Help!
 
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If his contact lenses are "ideally prescribed" I take that to mean perfect vision at infinity. So does it matter what the refractive power of the contacts is?
 
rude man said:
If his contact lenses are "ideally prescribed" I take that to mean perfect vision at infinity. So does it matter what the refractive power of the contacts is?
I figured it out. I had to subtract 0.278 m - 0.023 m instead of adding. The correct answer was -3.92
 
Altagyam said:
I figured it out. I had to subtract 0.278 m - 0.023 m instead of adding. The correct answer was -3.92
OK, I misread the problem anyway ...
 

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