I'm glad my notes helped
I think it's easier to study all of the ethical principles together in one big group that covers everything, so just the normal confidentiality, voluntary participation, withdrawal rights, informed consent, deception, debriefing, beneficence, justice, integrity, respect for persons, and anything else I may have missed. It should all be in your textbook, if not, my notes have a lot of the research methods stuff right at the end.
You don't really have to study research methods in visual perception separately from the normal research methods. The only difference is that on the exam they might give you a scenario describing some kind of visual perception experiment and you have to apply your knowledge of research methods to it. If that makes sense...
What do you mean by 'response to light'? (sorry, it's been awhile since I've done visual perception). Do you mean the visible light spectrum or information about photoreceptors or how light physically enters the eye? Or all of those things?