A lipoma is a benign tumor made of fatty cells. They might be found in many parts of the body. Depending on the tissue they are related to, they might be divided in the following subtypes: angiolipoma (containing an unusually large amount of blood vessels, neural fibrolipoma (grows along nerves and puts pressure on them), and chondroid lipoma (related to cartilage tissue).
Lipomas usually do not need treatment, because they are benign. However, as with every other tumor, lipomas might put pressure on other organs. Malfunctions might occur if the pressure is too heavy. For example, putting pressure on a nerve might cause sensitivity or motility disorders. Putting pressure on specific nerves (optic nerve, for example) might cause specific symptoms (sight problems, double vision etc.).
In your case, the doctors might decide to remove the lipoma with surgery if it continuously affects vision and slowly worsens it, because the location is very specific. If the lipoma was located in another organ, then removing it might have not been needed at all.
Although there are many herbal medicines and alternative medicine treatments that are said to help treating tumors (usually by strengthening the immune system or by immunomodulation, no medical independent scientific studies can be found to either support or to deny these claims.
Since oxidants are known to be one of the potential causes for tumors, taking antioxidants might decrease the chances for developing malignant tumors.