External change. Usually, conjunctival carcinoma is asymptomatic. It often goes undetected even when observed by experienced eye professionals. It is often confused for a benign conjunctival growth such as a pinguculae or a pterygium. A patient may notice a flat growth or transluscent discoloring of their conjunctivae. A definitive diagnosis requires a biopsy and treatment with topical anti-neoplastic drops.
Different appearance. A discoloration on the surface of the eye or the inner lining of the eyelid. Also a change in a spot on the eye or lining of the eyelid should be evaluated by an ophthalmologist. Also, any lesions that suddendly bleed should also be evaluated. Good luck and have a great day!