 It could be an early warning sign of rosacea, a common facial disorder whose top trigger is the sun. Sixteen million Americans suffer from rosacea, but only a fraction are receiving medical treatment. Learn the early warning signs, facial redness, like a sunburn that lingers and seems to be getting worse, visible blood vessels and bumps and pimples. In some people, rosacea can also affect the eyes, causing irritation that could even lead to vision loss.