Uncorrected	Corrected
		Short Sighted (myopia) This is where when uncorrected light focuses in front of the retina and a minus lens (thinner in the centre) is needed to correct.

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Long Sighted (hypermetropia) This is where when uncorrected light focuses behind the retina and a plus lens (thicker in the centre) is needed to correct.	Uncorrected	Corrected

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Uncorrected	Corrected
		Astigmatism. This is where when uncorrected light focuses in two separate planes i.e. not one point of focus but two. A lens that can focus light in two separate planes is needed to correct.