What could have been in the shirt of Yusuf (Joseph), peace be upon him, to cause the healing of his father's eyes, and is it a divine miracle or a scientific wonder?

The books of Tafsir (exegesis) have narrated that Yusuf's shirt, which he sent to Ya'qub, was from Paradise, and that it was the cause of Ya'qub's eyesight being restored. It is said that Jibreel brought it down to Ibrahim when Nimrud cast him into the fire, and it continued to be inherited by the prophets. Ibn Ashour commented on this narration, saying: "And it is far-fetched what was said: that the shirt was the shirt of Ibrahim, peace be upon him, even though Yusuf's shirt was brought by his brothers to their father when they brought it with false blood..." The more apparent view is that sending the shirt was a sign to Ya'qub of the truthfulness of Yusuf's brothers in what they were conveying to their father, and Ya'qub's healing was a karamah (miracle/honor) from Allah for Yusuf and glad tidings for him.