1. **Not eye-safe**: MAC glitter is often made from plastic (PET) and can cause serious eye irritation or scratches if used near the eye area.
2. **Cosmetic-grade only on sealed skin**: It is intended for face and body art, not for the immediate eye zone, unless labeled as “cosmetically compatible” flakes.
3. **Requires glitter glue**: To prevent fallout and improve adhesion, it should be applied with a specialty gel or adhesive, not standard eyeshadow primer.