Not sure how a loupe would help
http://www.ebay.co.uk/itm/Pocket-Jeweller-Lens-40X-25mm-Eye-Glass-Magnifier-Loupe-Magnifying-LED-Light-New-/310683194385?pt=UK_Jewellery_Watches_JewelleryBoxes_Supplies_CA&hash=item4856295411
unless ive got the wrong end of the stick
Here you go
http://www.ebay.co.uk/itm/GGS-3X-LCD-Viewfinder-Eyecup-Loupe-Lens-for-Canon-EOS-7D-5D-Mark-II-Nikon-DSLR-/110755995453?pt=UK_Photography_Viewfinders_Eyecups&hash=item19c9925f3d