Did you have high anaemia, blood pressure or diabetes during pregnancy? Particularly, diabetes and high blood pressure are known to have damaging effect on the nervous layer of the eye (retina). Also get your eye tension checked for glaucoma. If diabetes or high blood pressure, please report to the physician and get properly treated. Please get retinoscopy done from the ophthalmologist. That will reveal whether there is any damage to your retina. Are you sure you had perfect normal visual acuity before pregnancy? If so detailed investigation from the ophthalmologist is needed.