Astigmatism Flashcards
Astigmatism wherein the cornea has an unequal curvature on its anterior surface.
Corneal Astigmatism
Astigmatism wherein the crystalline lens has an unequal curvature on its surface or in its layers.
Lenticular Astigmatism
Residual astigmatism comes from which parts of the eye?
Posterior Corneal Surface
Lenticular Surface
Zonules
____________ is when the two principal meridians are perpendicular to each other.
Regular Astigmatism
With-the-Rule Astigmatism in minus cylinder form falls on what meridians?
1-30 and 150-180 (horizontal meridians)
Against-the-Rule Astigmatism in minus cylinder form falls on what meridians?
60-120 (vertical meridians)
________________ is when the two principal meridians are NOT perpendicular to each other.
Irregular Astigmatism
________________ is when one principal meridian is focused on the retina and the other falls behind the retina.
Simple Hyperopic Astigmatism
When both meridians are focused in front of the retina.
Compound Myopic Astigmatism
When one meridian fall in front of the retina and the other is behind the retina.
Mixed Astigmatism
Contact lenses for astigmatism.
Toric Contact Lenses
Lenses for astigmatism.
cylindrical or sphero-cylindrical lenses
Charts used to detect astigmatism.
Clock dial and Fan Dial
________________ is when one principal meridian is focused on the retina and the other falls in front the retina.
Simple Myopic Astigmatism
When both meridians are focused behind the retina.
Compound Hyperopic Astigmatism
