What is the ruling on corneal grafts for patients suffering from corneal opacities who are in dire need of such procedures? The donor tissue is harvested from a deceased donor within two to three hours after death, and the procedure is performed by specialized physicians.

There is no objection to undergoing such a procedure if the situation is as described in the question, and if the procedure involves harvesting only a small portion of corneal tissue from the deceased donor; the eye itself is not removed and remains intact; the patients are in genuine need of the operation; and qualified physicians determine that there is no alternative treatment available.

It is established in Islamic law that a greater harm may be averted by means of a lesser one. In this case, the greater harm would be the loss of sight suffered by a living person, while the lesser harm is the use of tissue from a deceased donor to provide a necessary benefit to someone who is alive.

And Allah Almighty knows best.