Question:
Which of the following spectacle prescriptions is an example of Simple Myopic Astigmatism?
Which of the following spectacle prescriptions is an example of Simple Myopic Astigmatism?
Show Hint
Simple astigmatism = plano sphere + one cylinder; myopic means the cylinder is minus.
Updated On: Jun 23, 2026
- Rx (+) sphere
- Rx will be plano (-)
- Rx will be (-) sphere
- (-)(+) (+)(-) on both 90 and 180 degree axis
Show Solution
Verified By Collegedunia
The Correct Option is B
Solution and Explanation
Step 1: In simple astigmatism one principal meridian is in focus (emmetropic) and the other is not. So the spherical component is zero ("plano") and the refractive error is corrected entirely by a cylinder.
Step 2: In simple MYOPIC astigmatism the out-of-focus meridian is myopic, which is corrected by a minus cylinder. Therefore the prescription reads plano with a minus cylinder, i.e. "plano (-)". That is option b.
Step 3: Why the others are wrong: a "(+) sphere" (option a) is simple hyperopia (a pure spherical plus correction), and a "(-) sphere" (option c) is simple myopia, not astigmatism, because both meridians share the same error. Option d, with opposite-sign powers in the two meridians (one plus, one minus), describes mixed astigmatism.
Step 4: So the only entry with a plano sphere plus a minus cylinder, the signature of simple myopic astigmatism, is option b.
Step 2: In simple MYOPIC astigmatism the out-of-focus meridian is myopic, which is corrected by a minus cylinder. Therefore the prescription reads plano with a minus cylinder, i.e. "plano (-)". That is option b.
Step 3: Why the others are wrong: a "(+) sphere" (option a) is simple hyperopia (a pure spherical plus correction), and a "(-) sphere" (option c) is simple myopia, not astigmatism, because both meridians share the same error. Option d, with opposite-sign powers in the two meridians (one plus, one minus), describes mixed astigmatism.
Step 4: So the only entry with a plano sphere plus a minus cylinder, the signature of simple myopic astigmatism, is option b.
Was this answer helpful?
0
0
Top NEET PG Ophthalmology Questions
- A female presents with loss of vision in the right halves of both eyes. Where is the lesion located in the optic pathway?
- A 65-year-old diabetic woman presents with painless loss of vision. The ocular findings are shown in the image below. What is the likely diagnosis and management for this patient?
- A 5-year-old boy presents with a small nodule on the sclera as shown in the image below. What is the likely diagnosis?
- The eye examination of a 20-year-old male shows a golden ring on the iris. What is the next investigation to diagnose the condition?
- What is the dye and filter used to diagnose corneal ulcers?
View More Questions
Top NEET PG Questions
- A patient hailing from Delhi presents with fever, arthralgia, and extensive petechial rash for 3 days. Lab investigations revealed a hemoglobin of 9 g/ dL, a white blood cell count of 9000 cells/mm3, a platelet count of 20000 cells/mm3, and a prolonged bleeding time. The clotting time was normal. What is the most likely diagnosis?
- Which of the following statements is true about Trichomonas vaginalis?
- A lady from West Rajasthan presented with an ulcer surrounded by erythema on the right leg. Microscopy of the biopsy from the edge of the ulcer showed organisms with dark staining nuclei and kinetoplast. What is the most likely causative agent?
- A child presents with a fever and a rash. Urine examination showed cells with owl's eye appearance. What is the most likely diagnosis?
- Infection with Clonorchis sinensis is associated with an increased risk of__?
View More Questions