We went to the vet today, despite the heavy rain and floods. He gave us Vitamin A on a syringe, and he applied some to my turtle. Later on, his eyes are starting to open!

When we got home, we tried to feed him, as he hasn't eaten for a while now... he's eating again!

I just want to thank you people who took time to view and reply.
On a side note, he didn't recommend the cod liver oil.