Nope, you had it right - diopters add. However, there are complicating factors. She may have some astigmatism. Her eyes might have different range of focus from yours, so your eyes might partially compensate for the reading glasses.JT Smith said:Or maybe I'm wrong.
And they are typically just sitting in open display on a shelf or at a small kiosk. They are meant to be tried on, so you don't even have to buy a pair to get an idea. Just look at your GF's Rx and as mentioned above, pick the pair or reading glasses with the complementary Rx in diopters and look around as you stand there. Can you say what her optical Rx is?JT Smith said:You can find those at a pharmacy.
Yes, a lens prescription can be reversed. This process is known as "flipping" or "reversing" the prescription.
There are a few reasons why someone might want to reverse a lens prescription. One reason is to correct for astigmatism, which can be achieved by reversing the cylinder and axis values in the prescription. Another reason is to compensate for the effects of aging on the eyes.
To reverse a lens prescription, the cylinder and axis values are flipped. For example, if the original prescription is -2.00 -1.50 x 180, the reversed prescription would be +2.00 +1.50 x 90.
Reversing a lens prescription can be done for most types of lenses, including single vision, bifocal, and progressive lenses. However, it is important to consult with an eye care professional before attempting to reverse a prescription, as it may not be suitable for certain types of lenses.
No, reversing a lens prescription is not a permanent solution. It is a temporary fix that can help improve vision in certain situations, but it does not address the underlying vision problem. It is important to regularly consult with an eye care professional to ensure the most accurate and effective prescription for your eyes.