<p><b>Once you do, you will love them.Convenience. No Put On And Take Off 100 Time Every Days</b></p> <p>There is an enlarged area at the bottom of the dual focus, and the degree above is zero. So you can wear it to observe a short distance, and you can s a long distance without taking off your glasses. If you are tired of put on and take off your glasses frequently, bifocal glasses are a good choice.</p>