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test Farsightedness
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Farsightedness

Farsightedness or hyperopia / hypermetropia is an eye defect in which a person cannot see sharply without accommodation of the eye. Farsightedness is caused by a too short eye axis or too little strength of the refractive system of the eye (cornea plus lens), which creates the image of objects ‘behind the retina’. In order …

Short-sightedness
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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 …

Girl glasses
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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, …