Which type of corrective lens is prescribed to neutralize the asymmetric corneal curvature of Astigmatism?
Answer and explanation
Correct answer: C. Cylindrical lens
- Step 1: In astigmatism, the cornea has unequal radii of curvature in different meridians (like a rugby ball instead of a sphere). Step 2. A cylindrical lens possesses refractive power in only one axis, equalizing the focal lengths across orthogonal meridians. Answer: Cylindrical lens. Why not the others: Spherical concave lens corrects myopia equally in all directions; Spherical convex corrects hypermetropia equally; Prism lens corrects binocular diplopia.
Practise more Medical Optics, Electrophysiology and Clinical Radiation.
Free questions with an explanation for every one, and full timed Medical College Admission Test (Bangladesh) mock tests.
More Medical Optics, Electrophysiology and Clinical Radiation questions
- Which anatomical structure of the human eye provides the greatest portion (approximately 70% or 40-44 Diopters) of total refractive power?
- What vision defect occurs when the eyeball is too long or the cornea too curved, focusing parallel light rays in front of the retina?
- Which type of corrective ophthalmic lens is prescribed to correct Myopia (Short-sightedness)?
- Which vision defect is corrected using a Convex (converging) ophthalmic lens?
- What age-related refractive condition involves gradual progressive loss of crystalline lens elasticity and near accommodation?
- What optical phenomenon enables flexible fiber-optic endoscopes to transmit illuminated images from deep body cavities without light loss?