Disposable contact lenses - where to buy? (Ho Chi Minh City)

Is there anyone who knows where I can buy disposable contact lenses in Vietnam? I am currently living in Da Nang and here it does not seem to be available anywhere. (I am currently using Focus Dailies but any international brand will do). If anyone know if they are available in HCMC please let me know, if you know an on-line shop even better!
Please note that I am not talking about the "coloured" types, but the regular old-fashioned ones to correct near-sightedness with!