Dear James: My neighbor’s security lights shine in and are annoying. Would louvered shutters or miniblinds be most effective? What size and on which windows would be best? — Alan R.
Dear Alan: Nighttime light pollution is definitely a problem and not just for neighbors. It has a negative effect on wildlife and their natural behavior. Highly directional security lighting is available to minimize this problem. Older floodlights can be fitted with shields to reduce the amount of annoying stray light.
Your three basic window covering options for blocking light from outdoors are curtains/drapes, miniblinds and shutters. They all are effective and will also provide more privacy. Shutters, particularly louvered ones, are not quite as effective for privacy as the other two because there will still be small gaps that someone may be able to look through….