What is the weakest glasses prescription you can get?

Plain Glass: I really wonder why this question is asked. I suppose you could get glasses with a plain glass lens if you wanted to wear the glasses as a fashion accessory, but did not need any correction for your own vision.

No prescription: Plain glass lenses can be worn for those who like how they look in glasses. If you are blurred when you read or look at distances, even a mild prescription may help you. Usually, people can avoid wearing glasses if they have prescriptions of up to 0.5 diopters; some individuals may feel more visually comfortable with even this low of a glasses prescription.