Police believe the incident, which happened in Cambuslang at around 11pm on Sunday, was a targeted attack.
Officers said the couple, an 81-year-old woman and an 80-year-old man, were at home when the two men forced entry, demanded money and assaulted them with a weapon.
The woman ran to the front garden of the Cairnswell Avenue property and alerted some neighbours, who attended to them while the suspects fled.
The attackers made off empty-handed through a lane leading to Rosebank Drive.
The elderly couple were treated at the scene by ambulance staff but did not need any more medical attention.
Detectives are appealing for information about the incident.
The suspects are described as being local men, aged 20 to 40, and of medium height and build.
At the time of the incident they were wearing dark clothing with their faces covered.
Detective Constable Iain McCulloch, of Cambuslang CID, said: “This was a terrifying incident for this elderly couple to endure. It is incredibly fortunate that the woman managed to alert neighbours who attended immediately.
“Early indications suggest that this was a targeted attack. We are analysing available CCTV and footage from the police helicopter, which was immediately tasked to this incident.
“We are currently progressing door-to-door enquiries to establish if anyone in the area has any further information which could assist in the investigation.
“As a community, we will not tolerate this type of criminality. Targeting those you perceive to be vulnerable is an especially insidious act.”
Anyone with information is asked to contact Police Scotland on 101.