Encountering Problems with Near Vision after 40. If you have never needed eyeglasses or contact lenses to correct distance vision, then experiencing near vision problems after age 40 can be concerning and frustrating. You may feel like you've abruptly lost the ability to read the newspaper or see the cell phone numbers.
A system of symbols used to represent special things. Example: In mathematical notation â means infinity.
In mathematics, an expression (or mathematical expression) is a finite combination of symbols that is well-formed according to rules that depend on the context.Mathematical symbols can designate numbers (constants), variables, operations, functions, punctuation, grouping, and other aspects of logical syntax.n general the meaning of expressions is not limited to designating values; for instance, an expression might designate a condition, or an equation that is to be solved, or it can be viewed as an object in its own right that can be manipulated according to certain rules.