NCAA rules and what action to take for injured player

What's your definition of gray shirt? Dropping now won't help him with the 10 semester limit. If he started the semester as full-time, that burns the semester (14.2.2.1). But if he can't play this spring due to the injury, he might be able to get a waiver for another year of participation.

by gray shirt I mean he worked out with the D1 team in fall , was not rostered  at took 10 hours of classes.  But he has played two years of Juco ball prior to the gray shirt year.   But I could be wrong and it was a redshirt.

It sounds like he has been enrolled as a full time student at the start of 6 semesters and has played 2 seasons? If so, I would say he has 4 full time semesters left to play 2 more seasons. If he can't play in the spring 2017 season because of the eye injury, he may be able to get an injury waiver for another 2 semesters. In any event, there's nothing he can do about this current semester, it counts against the 10 total.

If this young man's family is concerned about his ability to successfully complete his classes for this semester due to the swelling of his eye, they may want to consider the option of taking a medical withdrawal from his classes for this semester.  He might then qualify for a Medical Absence Waiver which would allow him to then prorate the credit hours that he's required to earn this year.  

I stress the "may" and "might" in my comment, because the other eye may be just fine, but if the surgery is impacting his ability to concentrate on his studies, that might be something they want to check out.