Can too much sun cause eye cancer?

In theory. In theory too much sun can cause melanoma of the retina. However, there is no hard data to prove or disprove this.
Eye cancer +sunlight. There is a strong correlation between sunlight exposure and skin cancers of the eyelids including melanoma and basal cell carcinoma. The incidence is much higher in light skinned races. If you have a suspicious lesion, see your ophthalmologist for evaluation. These tumors are of course mostly in older populations.