These Reading Knives have precision sharpened mirrored blades. With a long enough blade to reach the spines of most books, Reading Knife's smooth surface slides easily over their pages. An alternative to glasses for the hard-of-seer, Reading Knife enlargens the size of printed text by reflection of the letter on its angled surface. Dual Reading Knives are sold in each ornate set to reverse then rereverse each line of text as they guide your eyes down the page. Reading Knives also have knuckleduster page holder attachments. The right page Reading Knife is twice as long as the left page reading knife, so the book can be held open by insertion of the left book cover into the right page knife knuckleduster and right, left.
-- rcarty, Dec 04 2013

illustration http://imgur.com/XYpzejD
[rcarty, Dec 06 2013]

I'm normally pretty good at visualising, but in this case, a sketch would REALLY help. Particularly in explaining the optical path.
-- neutrinos_shadow, Dec 04 2013


Highly polished sharp things, mmmmm … [+]
-- 8th of 7, Dec 04 2013


Using a concave mirror, the mirror itself can invert the image. An example is looking behind yourself using the bowl of a spoon. In that case, it makes the image smaller as well. However I think that with the mirror held close to the line of text being read, it would be possible to get the curve right so it both inverts and magnifies, implementing this beautiful device in an even simpler and elegant single blade.

But I don't quite picture how the knuckleduster part works.
-- scad mientist, Dec 05 2013


Link
-- rcarty, Dec 06 2013


The right page holder, the longer one on the left, is longer IN function as a page holder because it wraps around the cover. The left knife is shorter in function as a primary reflector because it is held in the hand, and the knuckleduster does not function longitudinaly.
-- rcarty, Dec 06 2013



random, halfbakery