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Physiology & Medicine / Re: Why do optometrists dilate our eyes then do the exam?
« on: 05/04/2019 16:47:40 »
The wider your pupils are, the shallower your depth of field. Depth of field is the distance range over which objects in your vision will appear relatively in focus. With your pupils contracted and focused on an object 10 ft away, objects 7 to 13 ft away might look in focus, but with them dilated, it might drop to objects between 9.5 and 10.5 ft
By dilating your eyes and reducing your depth of field, they are making your eyes more sensitive in small changes in the prescription. In other words, when they ask you if "1" or "2" looks better, You'll see a larger difference with your eyes dilated than with them not, which allows them to fine tune the prescription more accurately.
By dilating your eyes and reducing your depth of field, they are making your eyes more sensitive in small changes in the prescription. In other words, when they ask you if "1" or "2" looks better, You'll see a larger difference with your eyes dilated than with them not, which allows them to fine tune the prescription more accurately.
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