4 months post blepharoplasty my scars are still very red. What can be done? Will I need a revision? (photos)

This would be the opportunity to surgically address any other unsatisfactory issues with your blepharoplasty such as lowering the upper eyelid crease, performing an anchor blepharoplasty to support the upper eyelid lashes. Generally it is best to wait a full 6 months after surgery for this work. It takes time to get consultations and get scheduled for this kind of work. I do not recommend returning to your original surgeon for this work. There was no reason that the blepharoplasty incision needed to extend this far laterally.

It looks like your wounds separated a bit while healing so it looks wide now laterally.  May be best to excise the scar and reclose.  Post-op I would start some laser treatments early on to help make sure that the scar looks good.  An option is to do some laser treatments now - combination of non-ablative and ablative fractionated resurfacing.  Not sure if it will help enough as the center of the scar looks depressed.  

As noted below you have options with regards to scar revision and postoperative laser treatment to try to get the redness to resolve quicker. I would follow with your surgeon to see if they are comfortable with revision prior to 6 months. Best of luck.

I think you have waited long enough post surgery to consider moving forward with scar treatment. First off I don't think another surgery or surgical scar revision is your best option. A very low risk option is to use a topical scar reducing cream such as Skinuva. A second option would be microneedling. Since the eyelid skin is very thin I would recommend going to a physician to have this done. The last option would be to have laser treatment of the scar. The last option would most likely give you the best results.