Can lip fillers cause blindness? Will icing the area to constrict blood vessels help minimize this risk?

Lip fillers are a wonderful and safe way to enhance and volumize the lips. The risk of serious complications is very low. In the rare event that a vessel occlusion occurs a trained, experienced injector will note it right away. An injection of fillers to the lips resulting in blindness would be even extremely rare.

Blindness has occurred from the use of cosmetic facial fillers. The incidence is extremely low.
The retinal artery an end branch of the external carotid Rhodri which also supplies many of the arteries on the face. The labral artery is distal to where the retina artery branches off and filler would have to travel retrograde in order to reach the retinal artery from a lip injection which is highly unlikely.
The incidence of blindness are more related to injection around the eyebrows and corners of the nose.
I suggest you talk to your provider about risks and let them explain the procedure risks and how to minimize them.
Personally I prefer to pre-inject lidocaine with epinephrine prior to injecting lip fillers. that causes profound vasoconstriction and severely minimizes the chance of vascular injury including minimizing the chance of bleeding and bruising.
Each provider will have their own methods.
The chance of blindness from lip fillers is probably much less than the chance of mortality from driving to your doctors appointment.
Best,
Mats Hagstrom MD