I'm sorry to hear about your being housebound, but it sounds to me like you may need a new prescription. My prescription is similar to yours(-3.25 strongest with astigmatism), but my ability to read has been declining it turns out I've developed presbyopia, which means I need bifocals or to use reading glasses.
The amount you would need to change your prescription for reading glasses is whatever is in the ADD box on your glasses prescription. If your prescription doesn't have anything in that box, then you'll need to get a new prescription and since you haven't had one in 5 years, it sounds like it's time for new one. Zenni explains this and about PD in the Your Prescription section under Info. Wikipedia also has a good article on Pupillary Distance that explains near and far PD. http://en.wikipedia.org/wiki/Pupillary_distance As for being 0.5mm off in each lens, I can't really say. I know someone who purchased a pair of glasses that had an incorrect PD, with one lens being off by 3mm, and they had problems in the lens that was off. She got a Walmart optician to measure the PD for her using a PD reader that the patient looks into like binocculars, and got 29.5/32.5. She had glasses made from that and in order to see out of one eye without pain, had to push the glasses toward her nose. I measured it using a paper ruler printed from one of the glasses sites and with a PD ruler I found online, and did the measurement multiple times and got between 58-60, so we went with 59, and her glasses seem to fine. I'm a bit surprised by that considering I've never worked in nor do I have any training in the optical field. I hope this has helped you. Good luck. RedStickHam On Jul 26, 12:06 pm, ellen <[email protected]> wrote: > I am housebound and thus unable to go out and get a new eye exam > without great difficulty. I need a new pair of glasses because, while > I used to be able to read up close with no strain wearing my usual > glasses (-3.0 in both eyes), I now find that I need to push them > further and further down my nose in order to be comfortable when > reading. I'm running out of nose length! My near vision is still very > good, and I don't need the typical sort of reading glasses. I would > just like to have a slightly weaker pair of glasses for when I read or > use the computer. > > Here are my questions: > > Approximately how much weaker would the prescription have to be to > satisfy this need? > > Would I need to slightly reduce the pupillary distance to make this > work better? By moving my current glasses down my nose when I read, > aren't I in effect reducing the PD? If that were the case, how much > would I have to reduce it by? > > According to my records at the store where I last bought a pair of > glasses over five years ago, my PD is OD 30.5 mm, OS 31.5 mm. I did a > fair bit of looking and "trying on" at Zenni and was hoping to buy a > pair of glasses, but when placing my order I found that they don't > allow for two numbers for PD. How much difference will it make if PD > is off in each eye by 0.5 mm? I'm pretty sensitive and prone to > eyestrain. > > Would going with a higher index lens and having a weaker rx mitigate > the PD issues to some extent? > > Thanks, > Ellen -- Check us out at the oft-updated http://glassyeyes.blogspot.com! You received this message because you are subscribed to the Google Groups "GlassyEyes" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/glassyeyes?hl=en
