Correcting vision problems using lenses
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Correcting Vision Problems Using Lenses. Light and Geometric Optics. Refractive Errors – Hyperopia (Far- Sightedness). those who are farsighted have difficulty focusing on distant objects and are even blurrier up close;

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Correcting Vision Problems Using Lenses

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Correcting vision problems using lenses

Correcting Vision Problems Using Lenses

Light and Geometric Optics


Refractive errors hyperopia far sightedness

Refractive Errors – Hyperopia(Far- Sightedness)

  • those who are farsighted have difficulty focusing on distant objects and are even blurrier up close;

  • caused by an eyeball that is too short, and a cornea that is too flat

  • light rays from nearby object diverge more strongly than the ones from faraway objects;

  • the light rays focus at a point behind the retina;

  • can be corrected using convex lenses


Refractive errors myopia nearsightedness

Refractive Errors - Myopia (Nearsightedness)

  • - individuals can see objects that are close clearly, but cannot see far away;

  • happens when light rays focus in front of the retina;

  • caused by an eyeball that is too long, and a cornea with too much curvature (i.e., too much focusing power);

  • corrected by concave lenses;

  • - diverging lenses cause the light from distant objects to diverge as they approach the eye.


Refractive errors astigmatism

Refractive Errors - Astigmatism

  • occurs along with nearsightedness or farsightedness;

  • due to a cornea that has an irregular shape

  • light entering the eye from different directions is focused different amounts;

  • or example, light entering vertically may be focused more than light entering horizontally;

  • light is focused the same amount in each axis  blurred vision;

  • letters appear slanted or have tails, and the affected eye sees double;

  • astigmatism is treated similarly to nearsightedness and farsightedness, but with different amounts of treatment on each axis.


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