There are two main types of patch. The first one is that adhesive patches stick to the skin. Advantages : hard to peak around, come in 2 sizes, various brands have different types of adhesive (some stickier than others to suit individual needs), available in most pharmacies and various websites on the internet.Disadvantages: Can irritate the skin, can hurt coming off, may be the more expensive option. The second kind is that felt patches are made to slip on over glasses. Advantages: rarely irritate the skin, washable, reusable, overall cheaper than adhesive patches, available in many optical shops and various websites on the internet. Disadvantages: sometimes easier to peak around, can only use these if the child is wearing glasses. Hope this helpful.