Hyperopia + Converging Lens Question

[regeneration]

Hi,

When a person is farsighted, I understand that they use a converging lens. Doing this would make any object within the focal point of the converging lens become a virtual upright image that is large than the object itself (magnifying the object size).

However, does this mean that if one were to look at an object outside the focal point of the lens, images would invert? i.e. since the object is beyond the focal point of the converging lens, a real, inverted image should form.

This seems impractical for everyday use, but I don't have a converging lens on hand, so I can't try this out myself. Do images far away actually invert?

Thanks!

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[regeneration]

Anyone know?

 

[BerkReviewTeach]

Great question. Ever notice how older people peer over their reading glasses when looking at you? They do this for the very reason you just described. As long as the object is inside the focal length of the congering lens, then it will generate a larger upright image that is farther away than the object itself (and thus appears larger than the actual object). This allows the reader to see the image of the printed words more clearly than the actual words on the page.

But when they look up, if you are beyond the focal length of the glasses then an inverted real and smaller image of you forms in the glasses, so their eyes see you and the tiny, inverted image of you. I assume this is why they make bifocals for people who develop farsightedness with age. And the focal length must be pretty big for the converging lens so that things within a few feet are magnified.