Plush toy eyes are primarily made from ABS (Acrylonitrile Butadiene Styrene), PS (Polystyrene), or Glass. For B2B buyers, the most critical factor is compliance with safety regulations such as EN71-3 (Europe) and ASTM F963 (USA). These standards ensure the eyes are lead-free, non-toxic, and phthalate-free. Additionally, for safety-conscious markets, you must ensure the eyes are 'Safety Eyes' with secure washers that prevent them from being pulled out, mitigating choking hazards for children under three.