NO IRRITATION: A hole that can be fixed on the glasses,convenient to use and no irration to skin.^ NO LIGHT LEAK: It made of 8 Light-shielding layers,Completely opaque and no light leak.More effecial to treat Amblyopia^ SOFT AND COMFORTABLE:Made of premium material.Pretty Soft, breathable and Comfortable.skin-friendly.^ LONG TERM FOR USING: It is reuseble,not disposable.save your money ^ Note:Shipping time is 5-12 days