Artificial tears (lubricating eye drops) replace your natural lubricating tears. You can buy most lubricating eye drops without a prescription. And you can use them as often as needed. These are not the same as eye drops used to ease redness or itching. Check with your eye doctor or pharmacist to be sure you buy the right drops.
Some lubricating eye drops have chemicals called preservatives. This makes them last longer inside the bottle. Your eyes may not handle these drops well. Or you may need to use them more often than you would like. If so, you may want to buy lubricating eye drops made without preservatives. Your eye doctor may also advise using a lubricating eye ointment at night.