A money-back guarantee for eyewear purchased online typically means that if a customer is not satisfied with their purchase, they can return the eyewear within 10 days of receiving it and receive a full refund. This type of guarantee can provide peace of mind for customers who are concerned about the fit or quality of the eyewear and may encourage them to make a purchase. However, it's important to note that the store might have some conditions to return the item, for example, the item should be in original conditions, and you should contact the store to get information about their return policy and process