Randy Moss Reveals He's Been Battling Health Issue, Asks For Prayers

Randy Moss asking for prayers for himself and his family ... 'cause he says he's been dealing with something internal -- and apparently it's affecting his eyes.

The NFL Hall of Famer took to his Instagram Sunday morning -- while working alongside his cohosts on "Sunday NFL Countdown" ... speaking to fans directly and telling them he's been battling some sort of health issues recently.

Moss doesn't go into detail about the exact issues ... but, he asks all the "prayer warriors" to keep him and his family in their thoughts -- so, it sounds fairly serious.

Randy then puts on a pair of sunglasses ... saying if people see him wearing them on the show, it's because of this issue he's dealing with -- not because he's making a fashion choice.

RM ends the message on an uplifting note ... telling fans not to worry 'cause he's got a great team of doctors around him -- before specifically telling men they need to get regular check-ups and blood work done.

Moss is one of the most dominant wide receivers ever ... racking up 156 touchdown catches and more than 15k receiving yards across his 14-year career.