Difference between revisions of Close-up glasses
Jump to navigation
Jump to search
No edit summary |
m (the distance to the object is not the focal distance. (Unless you want to argue that it is the virtual focal distance of the diverging lens that would be required to make objects at infinity appear to be at that distance instead, which is a perfectly valid way of thinking about it.)) |
||
| Line 20: | Line 20: | ||
The base point is an [[emmetropic eye]] with 20/20 vision. | The base point is an [[emmetropic eye]] with 20/20 vision. | ||
Everyone has a different level of myopia, and depending on this you can calculate the required amount of correction to see the object, based on how far away it is. | Everyone has a different level of myopia, and depending on this you can calculate the required amount of correction to just see the object, based on how far away it is. | ||
Firstly, find out the | Firstly, find out the distance from you to the object. In plain English, how far away is the object in centimetres? | ||
Type in the cm value you get into [https://endmyopia.org/focal-calculator/calc.html EndMyopia diopter calculator] to figure out the '''difference''' between your full strength prescription glasses, and what you actually need to see the screen. | Type in the cm value you get into [https://endmyopia.org/focal-calculator/calc.html EndMyopia diopter calculator] to figure out the '''difference''' between your full strength prescription glasses, and what you actually need to see the screen. | ||
| Line 38: | Line 38: | ||
So, you should use OD/OS -2.5/-1.5, if 60cm is the main distance you perform up-close activity. Simple! | So, you should use OD/OS -2.5/-1.5, if 60cm is the main distance you perform up-close activity. Simple! | ||
==References== | ==References== | ||
{{reflist}} | {{reflist}} | ||
[[Category:Articles]] | [[Category:Articles]] | ||