The eye patches are suitable for lazy eye, strabismus and amblyopia. They are easy to use just slide this patch on over the glass stem and wrap it around to cover the lens. The eye patches are made non-woven gauze material, washable and durable, these eye patches in black color that matchs your most glasses. The patches fit for most of the medium and small glass frame for kids, they can train the lazy eye to work properly. 12 pieces of eye patches, enough for daily replacements, help to keep your eyes clean and prevent them from inflection while having treatment. Colour: black Material: non-woven fabric Size: 10.5x5.2CM Package Contents: 12 * Eye Patches Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.