Stuff I don't know

Spexxvet · 11-09-2010, 01:36 PM

D=40/f, where D= dioptric power (your +1.25) and f= focal length in inches. Each .25 represents about 2 inches, when you are totally unable to accommodate. It looks as though you have some ability to accommodate, so your best bet would be to go to the store with your Blackberry and hold it at a comfortable length, then try different powers until you are comfortable. It may that you need more like a +0.75 or +0.50, but you'll be hard pressed to find less than a +1.00 in a store.

11-09-2010, 01:36 PM	#11
Spexxvet Makes some feel uncomfortable Join Date: Dec 2005 Posts: 10,346	D=40/f, where D= dioptric power (your +1.25) and f= focal length in inches. Each .25 represents about 2 inches, when you are totally unable to accommodate. It looks as though you have some ability to accommodate, so your best bet would be to go to the store with your Blackberry and hold it at a comfortable length, then try different powers until you are comfortable. It may that you need more like a +0.75 or +0.50, but you'll be hard pressed to find less than a +1.00 in a store. __________________ "I'm certainly free, nay compelled, to spread the gospel of Spex. " - xoxoxoBruce

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