None: This is simply, as you have described, manually comparing lenses to achieve the optimum correction. It is a method of trial and error usually using a trial frame. It can work well and is usually less threatening for a child than the device used for older children and adults called a phoropter.
Answered 2/5/2017
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A doctor has provided 1 answer
A doctor has provided 1 answer
A doctor has provided 1 answer
A doctor has provided 1 answer
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