A man wears glasses. From the normal position, he gradually removes them, all the time looking through the lenses of his glasses. When moving away, visible objects appear to him to be decreasing. What kind of glasses does he wear: for nearsightedness or farsightedness? With one eye a person looks through the spectacle glass, and with the other, in addition to the glasses, at a distant object, combining both images. The second image received by the naked eye appears to be 1.5 times larger than the first. In this case, the distance of the spectacle glass from the eye is 20 cm. Determine the optical power of these glasses.

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