Understanding Corrective Lenses: Examining Reversed Prescriptions

  • B
  • Thread starter Flyboy
  • Start date
  • Tags
    Lens
  • #1
Flyboy
Gold Member
317
417
My girlfriend has started wearing corrective lenses to address some nearsightedness and I'm not fully understanding what she's going through, or what the difference is for her with and without glasses. I was curious if you basically reversed the prescription of the lenses, would it take my normal vision and give me an idea of what she's seeing without the lenses?
 
Science news on Phys.org
  • #2
I believe that to first approximation that the diopter powers of lenses are additive. So if your friend has a correction of, say, -3.0 diopters you should be able to get a sense for what her uncorrected eyesight is like by wearing +3.0 "reading" glasses. You can find those at a pharmacy. They don't require a prescription and they are inexpensive.

Or maybe I'm wrong.
 
  • Like
Likes sophiecentaur and berkeman
  • #3
JT Smith said:
Or maybe I'm wrong.
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.

A better test is to compare the distances at which you and she can read, for example, street signs.
 
  • Like
Likes berkeman
  • #4
JT Smith said:
You can find those at a pharmacy.
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?
 
  • #5
Not off the top of my head, wanted to make sure I was understanding the physics right.

I do know she has a little prism to hers, which I don't think reading glasses have, but the reading glasses is a good idea for an approximation.
 
  • #6
If 'prism', that suggests a degree of astigmatism. Try rotating her glasses while looking through them. The result may be disconcerting as eg verticals blur vs horizontals, then vice-versa...
 

FAQ: Understanding Corrective Lenses: Examining Reversed Prescriptions

What are corrective lenses and how do they work?

Corrective lenses are specially designed lenses used to correct refractive errors in the eye, such as myopia (nearsightedness), hyperopia (farsightedness), astigmatism, and presbyopia. They work by altering the path of light entering the eye to ensure it focuses correctly on the retina, thereby providing clearer vision.

What does it mean to have a reversed prescription in corrective lenses?

A reversed prescription in corrective lenses refers to a situation where the prescription values for one eye are mistakenly applied to the other eye. This can lead to significant visual discomfort and impaired vision, as each eye receives an incorrect correction.

How can I tell if my corrective lenses have a reversed prescription?

If you experience symptoms such as blurred vision, headaches, dizziness, or eye strain shortly after getting new glasses or contact lenses, it is possible that your prescription may have been reversed. It's important to consult with your eye care professional to verify and correct the prescription if necessary.

What are the potential effects of wearing corrective lenses with a reversed prescription?

Wearing corrective lenses with a reversed prescription can cause a range of issues, including visual discomfort, double vision, headaches, and difficulty focusing. Over time, it can also lead to eye strain and fatigue, making it crucial to address and correct the issue promptly.

How can I prevent getting a reversed prescription in my corrective lenses?

To prevent getting a reversed prescription, ensure that your eye care professional conducts a thorough eye examination and double-checks the prescription values before finalizing your lenses. Additionally, when receiving new glasses or contact lenses, take a moment to verify that the lenses match the prescribed values for each eye. If any discrepancies are noticed, report them immediately to your eye care provider.

Back
Top