Keep in mind, this is not my fish but rather one I am thinking about taking on if I can help it so please forgive the lack of information here.
There are 5 Oranda Goldfish in a (90 Litre/23 US Gallon) Aqua One AR-620, all of which range from roughly 9-17cm from tip to tail.
Tank has a lot of algae buildup, particularly on corners of the tank, filter and ornaments. They were being fed at the time of photos being taken so water is quite messy- can't be sure of how often it's like that.
Regardless, there's one fish slightly smaller than most of the group (is a tad bigger than the 9cm) who has two damaged eyes that look like they aren't going to make it and I'm unsure of whether or not it'd benefit from coming into my care or not. I have a 10gal hospital tank I could put it in, or if it's healthy enough and I really need to I could move my axolotl to the 10gal and put the goldfish into my 30gal until I can find it a home. I don't really have anything for you to go on aside from the information I provided and some pictures.
I'd really like to know what people though about whether or not it'd survive (and recover) in it's current environment?
If it looks promising I'm happy enough to leave it there as I'd have to ship it to me and wouldn't want to cause unnecessary stress but if its not likely to survive where it is I'd like to take it on and try and help.