I am sorry to hear that. You must have ignore the proper prevention of your eyes. The sun will emit some dangerous invisibly lights like invisible infra-red or ultra-violet radiation leading to retina burn. Further, retina burns can be caused unconsciously, especially when you have a long time outdoor activities, even on cloudy days, or go out during 10am-2pm, where the sun’s UV rays are at their strongest. Besides, your contact lenses may not have built-in UV protection. Keep it in mind that UV can not be filtered by the cloud. Also, scientists have already proved that prolonged and excessive sun exposure can do a lot of damage to our eyes in the long run. Our white part of the eye may inflame the conjunctiva,called photokeratitis, including the redness of the eyes or discomfort. Don't worry, it can be remedied easily though. What is more, you can avoid permanent damage to your sight by using lubricating eye drops and anti-inflammatory drops.