I can clearly see the incision line after skin pinch Blepharoplasty. Is it supposed to be invisible? (photo)

you can see the scar here, which is completely normal at one week post-op.  The skin in this area is very thin and with time this scar should disappear.  While laser can improve the scars, it is almost never needed in this area. 

However, try to be patient.  This is a very good looking incision line for only being one week out from surgery.  Generally no, fractional laser and unfractionated CO2 laser will not improve the scar if it does not ultimately heal to your satisfaction.  It is possible to revise these scars but this is seldom necessary.  Six months is an appropriate time frame and a great deal of healing will occur in this time frame.

You are correct that it can take at least 6 months (and sometimes longer) for the scar to fully heal after a skin pinch lower blepharoplasty.  You should not need to do anything other than give it more time to heal and use sun protection to your eye area.  The incision normally does heal very over time.