Sheffield University led on a particularly cruel study carried out in India to investigate the use of synthetic alternatives to human donor membranes for corneal regeneration. Synthetic membranes were glued to one eye of 14 rabbits and the eye sewed shut.  Four rabbits were killed midway through and the rest were left for 29 days with ocular lesions and conjunctival congestion. These rabbits would have felt severe pain and burning to their eyes whilst confined to their barren metal cage or worse, restraining stocks.

Source: Animal Justice Project