I have a pet peeve about eyedrops sold in drugstores to unsuspecting consumers:

Many drops contain ingredients that are NOT safe for frequent daily use, but without requiring substantially different labeling that could indicate to consumers that they differ from drops that ARE safe for regular use.

Here are two types of problematic ingredients in widespread use in over-the-counter drops:

• Toxic preservatives, which cause dry eye;
• Redness relievers, which have a rebound redness effect.

Now, drugstore shelves contain mostly a mixture of the following:

1. Lubricant drops, preservative free
2. Lubricant drops and gels, preserved with mild or "dissipating" preservatives
3. Lubricant drops, preserved with benzalkonium chloride (BAK), the most toxic preservative in common use
4. Allergy drops, containing antihistamines and in some cases lubricants as well, and mostly preserved with BAK
5. Redness relievers, some of which contain lubricants, and all of which contain preservatives, most BAK
6. Multi-purpose drops, containing lubricants and/or redness relievers and/or antihistamines AND mostly preserved with BAK

Those who are under the care of a doctor and diagnosed with dry eye are likely, though not certain, to know that they should try to stick with preservative free drops. It used to be the case that that guideline could keep them on the straight and narrow. However, we're now seeing more multi-symptom drops coming on the market in preservative free multidose packaging that have additional ingredients not necessarily safe for frequent use.

Meantime, what about all the people with early, mild, maybe increasing symptoms, who are not seeing a doctor yet, or who have had only limited discussion of dry eye at their annual exams and perhaps haven't bothered to mention to their doctor exactly what over-the-counter drops they are using?

Under FDA regulations, ANY of the types of drops mentioned above can prominently advertise themselves for symptoms like dry eye, burning, and irritation of the eyes - because they contain a lubricant (in addition to other active ingredients). And while categories 4 through 6 tend to be grouped somewhat separately on the shelves, they aren't always, and even if they are, there's nothing obvious showing how they are different.

So how does a consumer know what is safe? By reading the label?

I wish that were true. Let's look at how much warning we actually get from the labels, specifically about these ingredient concerns:

1. The redness reliever warning

All drops containing redness relievers say: "Overuse may produce increased redness of the eye". Great, you say, I'll be careful. But, what does "overuse" mean? You go back and read the directions, which say "Instill 1 to 2 drops in the affected eye(s) up to four times daily". Excellent! I can use them four times a day and be fine! 

Six months, or maybe three years, later, you finally see a cornea specialist, and learn how much harm, perhaps irreversible, was done by chronic use of redness relievers. This happens to a lot of people.

In some theoretical world somewhere, this harm could be prevented by reading...

2. The 72-hour warning

All six of the eyedrop categories I mentioned contain language saying, roughly, "Stop use and ask a doctor if you experience any of the following...". One of those criteria is, roughly, "Condition worsens or persists for more than 72 hours. Sometimes it's one bullet point, sometimes two, but the gist is the same.

Yes, that type of language is on everything from preservative free artificial tears to BAK-preserved vasoconstrictor/antihistamine/lubricant drops. In these days of drowning in disclaimers, we all tend to tune out all this "boilerplate" language as just so much background noise. It looks, and is, exactly the same across a wide array of products.

How is anyone supposed to know the difference, without being a pharmacist (or a dry eye veteran like most of the people reading this post)? People with chronic dry eye use preservative free tears for years. Obviously they're not going to "stop use" because their years-long condition "persisted" beyond 72 hours. People with intermittent symptoms, if they even read that part of the label, will probably quite rightly understand it as it's intended: "If your eyes are icky, you might have an eye infection, so don't be stupid: if they stay mucky for a few days, go see your doctor." This type of warning just doesn't seem relevant to mild eye irritation or mild dryness. If you continue to feel dry, or burning, or itchy, or scratchy, or whatever is going on, you will continue  to use eye drops, and there is nothing on the label that seems designed to tell you that you shouldn't use this particular drop frequently or chronically.

3. Extraneous other warnings

Everything else will pretty much get dismissed as irrelevant or unimportant. Narrow angle glaucoma? Check - I don't have that. Replace cap after using? DUH. Stop and ask a doctor if... you experience changes in vision? Sure. Stop and ask a doctor if... you continue to experience redness and/or irritation? But I experience those every day. And so on.

How different it would be if there were a warning, in a box, saying "This product can cause dry eye if used more frequently than ....".  Ahhh. One can dream, at least.

Judge for yourself

Here are the warnings on two different eyedrops. How differently would you feel about the two, based on these warnings, as potential drops to buy for irritated, scratchy, sometimes bloodshot eyes?

1.

\

2.

#1 is Refresh Plus, which is harmless, and #2 is ClearEyes Complete 7 Symptom Relief, which has BAK, a vasoconstrictor and an antihistamine. 

Buyer beware.

And please, educate your non dry eye savvy friends.