For this sort of thing, you'll need to understand how video systems work & how the human brain & eyes work. Optics is only scratching the surface, while you also need to understand more about colour processing in different video systems & how the human brain processes light & colour information.
Simply put, you'll need more than a set of LEDs to create a sensor; you also need something to decode/process what the sensor has detected in a way that the human brain can understand (that is, if you intend for your sensor to act as a prosthetic eye).
Technology: something that's hated & cursed at by all engineers, technologists & technicians!
( Lousy modern technology!