Guinea pigs often keep their eyes open while they sleep. They do sometimes close them during deep sleep or while particularly relaxed and comfortable. Keeping their eyes open while sleeping helps guinea pigs stay alert and safe from harm.
Guinea pigs do not sleep for long periods at a time, preferring short naps throughout the day. When they sleep, they typically rest their heads on their front paws and may stretch out their hind legs, then remain motionless. Eye injuries and infections are common in guinea pigs, so a guinea pig that closes its eyes too frequently or shows signs of eye irritation should be examined by a veterinarian.