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प्रश्न
What is astigmatism? What is its remedy?
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उत्तर
- Astigmatism is the defect arising due to different curvatures along different planes in the eye lens.
- Astigmatic person cannot see in all the directions equally well. The defect due to astigmatism is more serious than myopia and hypermetropia.
- Astigmatism can be corrected using a lens which has different curvatures in different planes.
- In general, these specially made glasses with different curvature for different planes are called cylindrical lenses.
- Due to aging, people may develop a combination of more than one defect.
- If it is the combination of nearsightedness and farsightedness then, such persons may need a converging glass for reading purposes and a diverging glass for seeing at a distance.
- Bifocal lenses and progressive lenses provide solutions for these kinds of problems.
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