EyeWiki:Featured article/July 1, 2021
Featured Article for June 30, 2021
The eye’s total refractive astigmatism is a combination of corneal and lenticular astigmatism. Most astigmatism comes from the cornea. The average lenticular astigmatism is 0.5 diopters against-the-rule (ATR). The amount of lenticular astigmatism can be calculated by subtracting corneal astigmatism from the total astigmatism found by refraction. Since lenticular astigmatism is eliminated with extraction of the cataract only the corneal astigmatism is considered when planning cataract surgery. Accurate biometry is essential for correct IOL selection and the planning of astigmatism correction to achieve targeted visual results.