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 more advanced mathematics, a variable is a symbol that denotes a mathematical object, which could be a number, a vector, a matrix, or even a function.In this case, the original property of variability of a variable is not kept (except, sometimes, for informal explanations).n more advanced mathematics, a variable is a symbol that denotes a mathematical object, which could be a number, a vector, a matrix, or even a function.