Better to avoid, if cough is a lot.
Mainly due to 2 reasons -
1.If cough is due to infection, the eye can get infected post surgery, which will delay recovery
2. Excessive cough after cataract surgery may cause opening up of the incision site, thereby complicating things further.
Next Steps
Visit physician, and get physician clearance, and postpone cataract surgery until cough subsides.