Cataract surgery involves removing the natural lens of the eye and replacing it with an artificial lens (intraocular lens implant or IOL). The plastic artificial lens is permanent, requires no care, and can significantly improve vision.ataract surgery is indicated when the cataract impairs vision to the extent that it interferes with normal daily activities. Cataract extraction is one of the most frequently performed surgical procedures in the world. A cataract is a cloudy or opaque area in the normally clear lens of the eye.
There are 640 acres in a square mile -- there is no such thing as a square acre. And just in case you are interested, 43560 square feet in an acre. idiot detector Â· 1 decade ago
One acre equals 0.0015625 square miles, 4,840 square yards, 43,560 square feet or about 4,047 square metres (0.405 hectares) (see below).riginally, an acre was understood as a selion of land sized at forty perches (660 ft, or 1 furlong) long and four perches (66 ft) wide; this may have also been understood as an approximation of the amount of land a yoke of oxen could plough in one day.