If the bottle does not explicitly say it can be used with contact lenses, take the lenses out first. Most problems with drops come from preservatives and vasoconstrictors, not from the lubricant.
The four categories
1. Rewetting drops for contact lenses ✅
The only category designed to go in with lenses on. Usually sodium hyaluronate, HPMC or povidone, formulated not to disturb the lens material.
Use them as often as you need. If they are preservative-free, there is no practical limit.
2. Artificial tears for dry eye ⚠️
Many are fine with lenses; not all. The issue is preservatives, particularly benzalkonium chloride (BAK). A soft lens absorbs BAK and releases it against your cornea over hours — irritating more than the drop relieves.
If the label does not say, choose a preservative-free single-use vial. Those are almost always safe with lenses in, and they are the better choice for dry eye generally.
3. “Redness relief” drops ❌
Tetrahydrozoline, naphazoline and brimonidine do not lubricate. They constrict blood vessels. The eye looks white because you have reduced its surface blood supply, not because anything improved.
Two serious problems:
- Rebound redness. As the effect wears off the vessels dilate further than before, so you need another drop. The cycle is real and well documented.
- They hide the warning sign. A red eye in a lens wearer can be an early infection. Whitening it cosmetically delays diagnosis exactly when hours matter — see red eye with contacts.
4. Medicated drops ❌ unless told otherwise
Antibiotics, steroids, prescription antihistamines, glaucoma drops. The general rule: lens out, drop in, wait 15 minutes, lens back in — and only if your clinician said you may keep wearing lenses during treatment. With an active infection, usually not.
Solution is not a drop
This happens more than it should. Multipurpose solution contains disinfectants meant to act in the case, not on your eye. Putting it in directly stings and can cause epithelial toxicity.
Saline rinses; it does not lubricate or disinfect. See solutions compared.
Technique
- Wash and dry your hands
- Look up, pull the lower lid down, and let the drop fall into the pocket — not directly onto the lens
- Do not touch the bottle tip to your eye or lens
- Blink gently; do not squeeze your lids, which expels the drop
- One drop is enough. The eye holds about 7 microlitres and a drop is 30 or more — the rest runs down your face
If you need drops all day, something else is wrong
Drops are a patch. Needing them every two hours points at one of these:
- The wrong material for your tear film — moving to a silicone hydrogel or to dailies resolves many cases
- Meibomian gland dysfunction, which is treated rather than lubricated
- Incomplete blinking from hours of screen work
- A lens past its replacement date — see expiry
Worth saying at that level of detail in the appointment. “I need drops every two hours from about 3pm” is clinically useful; “my eyes are dry” is not.
Sources
- Literature on benzalkonium chloride uptake by hydrogel lenses
- TFOS DEWS II — ocular surface management
General information. Reviewed by Dr. Teresita Bollar, OD.
