I am usually in front of the monitor for an average of 9-11hrs a day and these glasses help me a lot! I do not feel the strain on my eyes anymore! The lens of this glasses are perfect and works for its purpose! The only downside I noticed is that whenever I pick up this glasses or putting it back to its case needs extra care. I do not feel that it is a cheap but rather a fragile material used on its frame. I admit that I am sometimes clumsy and I do not want it to break easily just by accidentally dropping from my table. Other than that, it is very lightweight and very comfortable to wear.