Is stroke a big risk for a blepharoplasty?

Blepharoplasty itself is not directly associated with an increased risk of stroke. However, as with any surgical procedure—particularly those done under general anesthesia—there is always a very small risk, especially in individuals with a strong family history of stroke or other vascular concerns.
Given your family history, it's completely understandable to feel cautious. The best course of action would be to speak with your primary care physician or a cardiologist before moving forward. They can evaluate your personal risk factors through a full medical workup, including blood pressure control, cholesterol levels, and any signs of underlying vascular issues. This will help ensure that you are in a low-risk category for elective surgery.
In some cases, blepharoplasty can also be performed under local anesthesia with or without light sedation, which may further reduce the overall systemic risk.

The overall risk of stroke with blepharoplasty is very low. If you have a genetic history of propensity for a stroke, you should discuss this with a hematologist and your primary care doctor who should be able to help you manage your preoperative and postoperative care such that your risk of stroke is reduced to that of the general population. There may be some tests and examinations that you should have done to rule out any predisposing factors to you having a stroke. Once these are known, they should be able to be managed. Again, the risk of stroke after blepharoplasty should be very low.

Blepharoplasty is a surgery that can be done in local or twilight anesthesia making a risk of stroke minimal to none. I am not sure that such a surgery would increase your risk of stroke. Good evaluation by your PCP is recommended. Good luck.