Which optical effect arises when a medieval lens distorts point light sources due to irregular grinding?

💡 Explanation

When a poorly ground lens focuses off-axis light, coma occurs because different lens zones focus light at varying distances from the optical axis, creating asymmetric, comet-like blurring. Therefore coma occurs, rather than chromatic aberration, spherical aberration, or astigmatism, each requiring distinct refractive or surface irregularities.

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• Which effect limited the geodetic accuracy of early Islamic astrolabes constructed using brass at varying temperatures?
• Which structural failure increases in timber-framed windmills when grain dust accumulates excessively inside the mill housing?
• Which structural innovation within 18th-century ship construction most directly enabled sustained transatlantic voyages carrying heavy cargo?
• Within Alhazen's work on optics, 'Al-Manazir', which algebraic problem limited derivation of accurate lens refraction angles?