Mr Cummins said Carroll (23) gouged his eye with his right hand as he lay on the street.
Carroll -- currently on loan at West Ham -- was in Dublin with team-mates on Sunday night. He was pictured at various locations wearing a white -- stained -- suit and white loafers.
The incident occurred at about 2.30am on Grafton Street.
Mr Cummins said he received treatment at Dublin's Eye & Ear hospital and is now on a course of antibiotics. He has a scratch on his eyeball and a burst blood vessel.
He was working on Grafton Street in the early hours of Monday morning when he saw Carroll enter a fast food outlet.
"A West Ham security guard came over to me and asked me not to take photographs.
"I told him I was just doing my job, but when I moved, he blocked my view," Mr Cummins said.
The security guard asked him to wait until the footballer was in a rickshaw, parked outside Burger King on Grafton Street, before taking any images.
Mr Cummins changed his lens when Carroll got into the rickshaw.
"Once I started taking shots, he got out of rickshaw and just went at me. I remember him saying, 'Get the camera'.
"I went backwards and I was over on the far side of the street. There was at least one security guard between me and him and at that point.
"Next thing I was on my back on the ground next to Burger King and he was still grabbing for my camera.
"I could feel his hand coming across my face, and his fingers digging into my eye. I started screaming, 'My eyes, my eyes'."
At this stage the footballer left the scene and a West Ham security guard remained.
"Once I started shouting 'My eyes, my eyes', everything seemed to stop," Mr Cummins recalled.
"I could hear security men saying 'Get him out, get him out', and one of security guys stood over me for the next couple of minutes.
"Somebody asked him what happened, and he said I dived to the ground. But I told him there was CCTV all over the place and it will show that I didn't dive."
Gardai have confirmed that the footballer is under investigation following the alleged incident. No arrest has been made.