If you have to feel sorry for anyone in the show, it’s poor Leonard Hofstadter. Apart from having to tolerate the, well we can’t call him insane, because his mother had him tested, we’ll call him kooky Sheldon Cooper, poor Leonard has a litany of problems. A complicated love life, and difficult living conditions aside, he is plagued by health problems. One of which is poor eyesight, which he corrects with glasses. But here’s the thing. The glasses that Leonard Hofstadter wears are fake. They are really fake. In fact, they are so fake they don’t even have glass in them.
So why would the prop department of the show take a risk by using glasses that were not real? First of all, in most circumstances, even with modern ultra high definition televisions, the viewer at home will not be able to see if any glass is present. It’s glass, and transparent. But even if there should be a reflection, most viewers would not be that observant. But there are other possible reasons.
Glasses are notoriously expensive. In most cases, the lens and frame can total several hundred dollars. This cost can be mitigated by using a cheap plastic frame, without any glass. The other possible reason is safety. If you have ever tried on a pair of glasses that belong to someone else you know why I say safety. It can be impossible to see through glasses that were not prescribed for your use. Why would any production company risk one of their main characters by giving him expensive glasses which he couldn’t see through?
Leonard’s por eyesight is caused by myopia, or nearsightedness. He has also revealed over the episodes that he suffers from being lactose intolerant, which is a recurring theme, sleep apnea, travel sickness, asthma and heart disease.