Polycarbonate is the most popular material for eyeglass lenses.It is a durable material that does not tend to shatter upon impact. It gets a spider web effect throughout the lenses made up of small cracks. It means that there will be less lens shards get into your eyes when lenses are broken. You can get polycarbonate lenses in several colors but if you are having your glasses custom made, always opt for the scratch-protective coating. It is usually included,however,the carbonate lenses are easy to scratch.