You could always give him two lenses and he could invert one over the other for macro-like magnification. Metering would be done with the body/viewing prism as it would be equipped.
APUG BLIND PRINT EXCHANGE
"Wubba, wubba, wubba. Bing, bang, bong. Yuck, yuck, yuck and a fiddle-dee-dee." - The Yeti