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Optical instruments

from short-sightedness can see nearby objects clearly but not distant objects. Figure
6.21 illustrates a myopic eye.
Focal point
Lens
Retina

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Cornea

Figure 6.21: Myopia

Correction of myopia
To correct myopia, rays of light from a distant object should be diverged before entering
the eye. Therefore, correcting the myopic eye involves the use of a concave (diverging)
lens, which forms the image of a distant object close to the eye lens. The image formed
by the glass lens is then focused onto the retina by the eye lens. Figure 6.22 illustrates
the correction of a myopic eye.
Image formed
before the retina

Distant object

Myopic eye

Virtual image created by the Image formed
diverging lens now acting Diverging lens on the retina
as an object

Myopic eye
Figure 6.22: Correcting a myopic eye

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