Multifocal lenses, a solution for presbyopia and cataracts

What are multifocal lenses? How many types are there? Do they correct presbyopia? And cataracts? Ophthalmologist José F. Alonso explains in this video. Subscribe: http://goo.gl/xhPzwR Follow us: https://plus.google.com/+Medicinatv   / medicinatv     / medicina_tv   More health: http://www.medicinatv.com/