# 👀 What diopter difference do you have between indoor and outdoor?

Hi everyone,

Just a general question. What diopter difference do people have generally in their daily lives between indoor and outdoor. I know that there are many variables that would influence it but I’m just after people’s general experience.

Im generally have a 0.75 diopoter difference between my normal full sunlit oudoor and well lit indoor environments.

Diopter Difference Indoor Outdoor
• 0.0
• 0.25
• 0.5
• 0.75
• 1.0
• 1.25
• 1.5
• 1.75
• 2.0

0 voters

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I’m not sure how accurately one can measure this on a Snellen. The best I can come up with is Snellen lines, and not diopters.

Uncorrected, I have some difficulty with the 20/25 inside, depending on time of day as well, get the 20/20 with some astigmatic deformation in full but not direct outside light, and get most of the 20/15 line with direct sunlight on the chart. How on earth can one convert this into diopters?

I saw that Andrew does not get any improvement outside. Maybe that is because he lives in a country where it rains 9 months of the year, and drips off the trees for the remaining 3. A bit like the Netherlands.

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This is merged from several slightly different conversions I found
20/200 = -2.00 to -2.50
20/100 = -1.5 to -2.00 (sometimes marked as -1.75 to -2.00)
20/70 = -1.25
20/50 = -1.00 to -1.25
20/40 = -0.75
20/30 = -0.5
20/25 = -0.25
20/20 = plano to -0.25
Interestingly this is what I found for the other lines
20/15 = plano
20/10 = plano (zero)

I’d put the “from 20/15 to 20/25” down to about 0.5D.

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Thanks, so I will vote accordingly.

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