There are three classification systems for individuals with visual impairment that are used by education professionals. To be declared legally blind, an individual must have visual acuity of 20/200 or less, or have a field of vision restricted to 20 degrees or less at the widest point. However, this federal classification system is used primarily to determine eligibility for adult agency services.
have an eye for something. to be good at noticing a particular type of thing She has an eye for detail. He had an eye for the unusual and the exotic which made him a very good shopping companion. See also: an, eye, for, have.
Book 24 reveals part of the origins of her feelings: Hektor was one of the few people in Troy who was nice to her. (Though she doesn't mention it at the time, she also has formed a bond with Priam, along father-daughter lines.) In the eyes of most Trojans, Helen means nothing but trouble.