This range may help with close up work such as reading, hobbies and detailed work like crocheting or model painting. Please note that the higher the strength the shorter the diopter, making the sight range very short. These glasses are manufactured to CE Standards and are tested in house to provide you with an affordable product. We are unable to test independently as these strengths fall outside normal ranges. Please be aware of this fact when purchasing. These glasses are intended for short term use only and should not replace prescriptive eye wear. Only an eye specialist can determine your personal visual needs. Should you suffer any headaches, migraines or eye strain whilst using this product you should cease use immediately.