Is there a cost-effective artificial tear?

I have been using sodium hyaluronate for artificial tears, and a bottle is only over 60 yuan. The most important thing is that there are no preservatives and side effects. Other artificial tears rely on preservatives to extend the shelf life, while the exclusive patent packaging of Hailu artificial tears effectively isolates the contact between artificial tears and air, making the shelf life as long as 3 years, even after opening the bottle.