I'd say the Cornea.The cornea <span>is the clear part of </span>eye<span> that is in front of the </span>iris<span> and the </span><span>pupil
</span>"Corneal transplantation<span> is a </span>surgical procedure<span> where a damaged or diseased </span>cornea<span> is replaced by donated corneal tissue, which has been removed from a recently deceased individual having no known diseases which might affect the viability of the donated tissue."</span>
