Mr. Carson is a character in Colony, he is Abraham Bowman's teacher at High School.
Bram calls this character "Mr. Carson", but he's credited as "Teacher".
Mr Carson has built a telescope and Bram offers to find a lens for it. Presumably in the abandoned area on the other side of The Wall that Bram has just visited with Pia. Bram gets a lens for Mr. Carson.
- The partly built telescope looks to be of the reflecting type, and so would probably need a mirror to complete it, rather than a lens as Mr Carson tells Bram.