Conformal and retro-conformal astigmatism refer to conformal and retro-conformal astigmatism, respectively, and they are both regular astigmatism.
Regular astigmatism is astigmatism in which the principal meridian of maximum and minimum refractive power are perpendicular to each other. Conventional astigmatism is astigmatism in which the principal meridian of refractive power is positioned at (90±30)°, while retro-conventional astigmatism is astigmatism in which the principal meridian of refractive power is positioned at (180±30)°.
Astigmatism is a refractive state in which the refractive power of the eye is different at different meridians, creating two lines of focus as well as a minimal diffuse spot. Patients with astigmatism may experience discomfort such as decreased visual acuity and double vision. Astigmatism can be corrected by wearing glasses to improve vision. If the patient has a strong desire to remove the glasses, refractive surgery can be performed to correct the astigmatism and improve vision.
It is recommended that patients with astigmatism consult a doctor to evaluate their condition and follow the doctor’s instructions for treatment.