Better pics under white light would help but it does look like ich. The cloudy eye can be a secondary bacterial infection from the ich or mechanical damage.
The best treatment for ich would be moving all fish into a quarantine tank and treating with copper (copper power or coppersafe) at 2.25 ppm for 30 days and to leave the display tank fishless for 60 days to starve out the disease.
In the first pic, it is tough to see ich spots, but it's left fin is damaged. In the other pics, it is pretty apparent that it has a moderate case of ich.
That medication is malachite green and nitrofurazone. I know the bottle says it is for FW and SW fish, but really, it does not work for saltwater fish, and you cannot use that in a tank with invertebrates in it.
Your two best options would be to treat all exposed fish in a hospital tank with either coppersafe at 2.25 ppm, or hyposalinity (low salinity) at a SG of 1.009. Both treatments would need to be run for 30 days, and then, the tank would need to be run fishless for 60 days to eliminate the disease.
Let me know if you need me to talk you through either of those treatments.