'''Astigmatic aberration''' is an [[aberration]] due to the irregular curvature of the [[ocular]] surface resulting in unequal [[refraction]] of the incident light in different meridians.
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'''Astigmatic aberration''' is an [[aberration]] due to the irregular curvature of the [[ocular]] surface resulting in unequal [[refraction]] of the incident light in different meridians.<ref>http://www.usaarl.army.mil/hmdbook/cp_011.htm</ref>