Hi, most eye problems are related to poor water. the results you have posted are fine, so its my guess that the person before you had a problem with their water. be it a shop or other persons. The best you can do would be maintain the water has it is and keep an eye on your oscar. you could add melafix but i would not start treatment at this stage as most small eye problems will clear with good water conditions. Whats the general condition of the fish as a hole, fins body, eating? if these are fine you have probably notice the problem early, thats a good thing. if you can get a close clear pic of the eye( very hard at best of times) it may be worth posting.If it gets larger re post and ask advice and retest water. dont worry to much there is a good chance it will clear and be fine.