(KFF Health News) – Checking the “donor” box on a driver’s license application, people may picture their heart, kidneys, or other organs saving another person’s life should the worst happen.

They are less likely to consider that tissues — corneas, tendons, bone marrow, skin, bone — are also covered by that checked box. In fact, donated tissues are collected much more frequently than organs, and corneas are the most commonly transplanted body part in the U.S., with nearly 51,000 transplants last year, according to the Eye Bank Association of America.

Organ and tissue donations are guided by different rules, with less transparency and what critics identify as more self-policing in the tissue donation industry. (Read More)