Will smoking/consuming marijuana after ptosis surgery affect the healing?

It would be best to not use marijuana after your surgery.  Anything you inhale other than air may have a detrimental affect on your healing.  Please ask your surgeon when it is safe to resume.

After 10 days, it would be rare for the eyelid incision not to have healed. Smoking cigarettes can definitely cause poor wound healing, but this is less likely to happen around the eyelids unless skin grafting is done.No data indicates that marijuana smoking affects the wound healing the same way as cigarette smoking.

Smoking cigarettes absolutely affects healing for most patients.  I've rarely seen patients heal incredibly well after facelifting even, but this is very very very rare.  Most often, smoking delays healing.  In general, you'll obtain the best and safest results by stopping smoking at least 6 weeks prior and keep from smoking for 6 weeks after.  It's a hard thing to do for sure, but it's your face you're dealing with.  As far as marijuana goes, there is no evidence to show change in healing in either direction.  However, the frequency of marijuana smoking is much less than cigarettes, so likely it would cause less damage.  Still there is no answer to this.