Roca cape lighthouse in Portugal, West most point of Europe ( Cabo da Roca) Vertical. Roca cape lighthouse in Portugal, West most point of Europe ( Cabo da Roca) Vertical. The obelisk with a large white cross at Cabo da Roca. It is a cape which forms the westernmost extent of mainland Portugal and continental Europe.
[Read more about children's eye exams .]. 20/20 vision (or really, 20/20 visual acuity) is considered normal vision, meaning you can read at 20 feet a letter that most human beings should be able to read at 20 feet.
Determining the Problem. 1  1. Observe for eyestrain. Think of how much time you spend staring at a screen everyday. 2  2. Know whether you have an infection. It's possible that your eye pain is due to an infection, such as conjunctivitis, known more commonly as pink eye. 3  3. Determine whether you have allergies.