That's great that it's working so well for your acne.  It's fine to keep using it as long as you are sunscreening every day.   I usually have my patients stop it one week before sunny vacations and cut down or stop in the summer if you are outdoors often.  It  will increase your sun sensitivity somewhat.   Use it at night because light inactivates it.   If you use it on the crow's feet area, be sure you are sunscreening well there.   The Dermalogica Total Eye Care is formulated for the sensitive eye area.  Dr. I