As for the bifocal glasses, the lower portion is for closer objects and the upper part for distance vision. The reason for this design is that people always put their heads slightly down when they try to read and write. However, customers will always get unsatisfied if they expect bifocal glasses types to deal with all situations. When it comes to computer use, the common bifocal design is not suitable, because the computer monitor is directly in front of the lenses. So choosing a pair of right glasses is very important. Before we make the decision, we should have a clear sense.