The Bible...not the glasses. Although, I need those too, so I probably should treasure them from a practical standpoint. Without them, I wouldn't be able to read! And then I would be a horrible archivist/librarian one day.
I seek you with all my heart; do not let me stray from your commands.
I have hidden your word in my heart
that I might not sin against you. Psalm 119: 10-11