The 31-year-old Englishman has been off the field since United’s away match against Birmingham on December 28th suffering from blurry vision.
The eye trouble was suspected to be a result from a head injury but specialists concluded that the problem is not football-related.
"The condition has been confirmed by a number of specialists who have all agreed that he (Scholes) needs to rest for a period of three months," said a statement on the club’s official website.
Scholes’ absence is one of several blows for the Reds who are currently missing Alan Smith for an ankle injury and John O’Shea, who picked up a rib injury during the match against Liverpool last Sunday.
United who clinched a 1-0 victory over Liverpool with Rio Ferdinand’s last-gasp header, are also without Argentina defender Gabriel Heinze and South African midfielder Quinton Fortune due to long-term knee injuries.
Scholes is expected to return in time for pre-season training.