Showing 2 Result(s)
Info

Short-sightedness

Short-sightedness or myopia is an ametropia in which the person (then called a myope) cannot see sharp objects far away, but nearby objects. Hence the name (close) myopia. Therefore, an object with a 0 vergence will not be sharply perceived and as the object approaches, the vergence will drop to a negative number. As soon …

Info

Positive and negative glasses

The nearest point from which one can still see clearly without difficulty is called the proximity point. In a normal (emmetropic) human eye this point is about 30 cm in front of the eye; even closer at a young age. The most distant point from which one can still see sharply is called the vertepoint, …