I had surgery (gas) for retinal detachment 8 weeks ago and got work clearance 2 weeks ago. please define heavy lifting restriction 3 months.

This you need to ask: The retinal surgeon, each doctor has his or her protocol, although similar, it is best to talk to the retinal surgeon.

25 lbs: In my definition, heavy lifting restriction is no more than 25 lbs. After retinal surgery, in my opinion, 8 weeks should be sufficient for that restriction to be lifted. You should follow the advice of your own surgeon, however.