Detailed Instructions: In this task, you are given a paragraph, event and an entity. The event is part of the given paragraph and it changes the state of the entity. Your task is to classify the state of the entity into three classes: 1) not exist, 2) unknown location and 3) known location. "not exist" means the entity doesn't exist in that state anymore. "unknown location" means the entity exists in that state but location is unknown. "known location" means the entity exists and location is known. 
Q:  "process paragraph : : The cornea helps to focus light. Light passes to the iris. The pupil within the iris expands or contracts to control the amount of light entering the eye. The retina converts the light that reaches the retina into an electric signal. Sends the signal to the brain. The brain translates the electrical signals into the images a person sees. ", "event : Light passes to the iris.", "entity : electric signal" 
A:
 not exist 