If he is being referred to a retinal specialist from another ophthalmologist, it is possible that it is a significant choroidal nevus (mole or freckle.) Depending on the size and thickness of the nevus there can be a chance of malignant transformation into a choroidal melanoma which is quite serious and often requires radiation plaque treatment to the eye. Again, just like a freckle on your skin, it all depends on size and characteristics, to determine if it is dangerous. For every 5000 choroidal nevi we see, maybe 1 at most might be a malignant melanoma. Now for ones big enough to be referred to a retinal specialist it might be more like 1 in 100.