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October 24, 2026
Glaucoma eye drops lower the pressure inside the eye, either by helping fluid drain out or by making the eye produce less of it. They are the most common treatment for glaucoma. Many people start with one drop a day, often a prostaglandin such as latanoprost used in the evening; others need two or three different drops, used one to three times a day. Drops control glaucoma but do not cure it, so they work only if you use them every day, including when your eyes feel fine. This page lists the main types, how often each is used, their side effects and how to put them in.
For the condition as a whole, including the types, symptoms, who is at risk, how it is diagnosed, today’s treatments and the trials testing nerve protection, read our glaucoma guide.
Yes. Lowering eye pressure is the only proven way to slow glaucoma, and drops are the most common way to do it. In the United Kingdom Glaucoma Treatment Study, people with newly diagnosed open-angle glaucoma used either latanoprost or a dummy drop. After 24 months, 15.2% of the latanoprost group had measurable visual field loss, against 25.6% of the placebo group. Latanoprost lowered pressure by 3.8 mmHg on average, against 0.9 mmHg with placebo. It was the first placebo-controlled trial to show that a pressure-lowering drop preserves the visual field.
Earlier, the Early Manifest Glaucoma Trial found that treatment cut the share of people whose glaucoma worsened over about six years from 62% to 45%, using laser plus a beta-blocker drop. Drops do not bring back vision already lost. Their job is to protect what remains.
The table lists the main drops used in the United States by class. Brand names are given for recognition; most are also available as cheaper generics.
| Class and examples | How it works, how often, main side effects |
|---|---|
| Prostaglandin analogs: latanoprost (Xalatan; Iyuzeh, preservative-free), bimatoprost (Lumigan), travoprost (Travatan Z), tafluprost (Zioptan, preservative-free), latanoprostene bunod (Vyzulta) | Help fluid drain out of the eye. One drop once a day in the evening. Common side effects are red eyes, irritation, longer and darker lashes, and a gradual darkening of iris color that can be permanent. |
| Beta blockers: timolol (Timoptic; Timoptic-XE gel), betaxolol (Betoptic S), levobunolol | Reduce the amount of fluid the eye makes. Usually twice a day; the timolol gel is once a day. The drug is absorbed into the body and can slow the heart or tighten the airways, so timolol is not used in people with asthma, severe COPD, a slow heart rate, certain heart blocks or heart failure. |
| Alpha-2 agonist: brimonidine (Alphagan P) | Reduces fluid production and increases drainage. The label says three times a day, about 8 hours apart. Side effects include allergic red, itchy eyes, dry mouth and tiredness. It must not be used in children under 2. |
| Carbonic anhydrase inhibitors: dorzolamide (Trusopt), brinzolamide (Azopt) | Reduce fluid production. The labels say three times a day. Dorzolamide often stings; both can leave a bitter taste, and brinzolamide can briefly blur vision. Both are sulfonamides, so tell your doctor about any sulfa allergy. |
| Rho kinase inhibitor: netarsudil (Rhopressa) | Improves drainage through the eye’s main outflow channel. One drop once a day in the evening. Red eyes affect about half of users; small deposits on the cornea and tiny bleeds on the white of the eye are also common. |
| Miotic: pilocarpine | Contracts the eye’s focusing muscle, which pulls the drainage meshwork open. Up to four times a day. It can cause brow ache, blurred or dim vision and poor night vision, and rarely a retinal detachment. Now used less often because of its side effects, mostly for some types of angle closure. |
| Combination drops: dorzolamide-timolol (Cosopt; Cosopt PF), brimonidine-timolol (Combigan), brinzolamide-brimonidine (Simbrinza), netarsudil-latanoprost (Rocklatan) | Two medicines in one bottle, which means fewer drops to remember. Cosopt and Combigan are used twice a day, Simbrinza three times a day and Rocklatan once in the evening. Each carries the side effects and warnings of both ingredients. |
It depends on which drops you use. One drop per dose is enough: a single drop is already more than the eye can hold, so extra drops just run out onto the cheek and waste medicine. A single prostaglandin drop lowers pressure for at least 24 hours, which is why these drops are used once a day. Beta blockers are usually used twice a day, and brimonidine, dorzolamide and brinzolamide three times a day.
More is not better. The latanoprost label warns that using it more than once a day may weaken the pressure-lowering effect or even raise pressure. If one drop is not enough, your eye doctor may add a second class of drop, switch to a combination bottle, or suggest laser.
The labels for prostaglandin drops, netarsudil and Rocklatan all say to use them once a day in the evening. In a 1995 Scandinavian trial, evening doses of latanoprost lowered pressure by 35% on average, against 31% for morning doses, a small but statistically significant difference. Other drops, such as timolol and brimonidine, are spread through the day. If an evening time is hard to keep, ask whether a different time or a different drop would suit you better rather than skipping doses.
Stinging, burning, redness and a dry or gritty feeling are the most common complaints. They can come from the medicine itself or from the preservative. Benzalkonium chloride is used in about 70% of eye-drop products and is known to damage the cells on the surface of the eye, a problem that matters more when drops are used for life. Preservative-free options include Iyuzeh and Zioptan (prostaglandins), Cosopt PF and timolol in single-use containers. Travatan Z and Alphagan P use gentler preservatives.
Prostaglandin drops can make eyelashes longer, thicker and darker and can gradually darken the iris. The iris change is expected to continue as long as the drop is used and may be permanent; eyelash changes usually reverse after stopping. Using the drop in only one eye can make the two eyes look different.
Eye drops drain into the nose and can be absorbed into the bloodstream. Beta blockers can slow the heart, lower blood pressure, worsen asthma or COPD and hide the warning signs of low blood sugar. Brimonidine can cause tiredness and dry mouth and is dangerous in babies and toddlers. Dorzolamide and brinzolamide are sulfonamides and can cause sulfa-type reactions. Tell the prescriber about asthma, lung disease, heart rhythm problems, kidney disease, sulfa allergy, pregnancy plans and every medicine you take.
Call if you notice swelling, a rash or itching around the eyes, persistent redness or pain, a change in vision, wheezing, dizziness or a slow pulse. Sudden eye pain with blurred vision, halos or vomiting is an emergency. Do not stop a drop on your own: there are usually several alternatives.
If you think a drop missed your eye, it is fine to put in one more. If you often miss, ask about an eye-drop guide or bottle aid, or have someone watch your technique at your next visit.
If you miss a once-a-day evening drop, skip it and use the next dose at the usual time. For drops used two or three times a day, use the missed dose when you remember unless it is almost time for the next one; then skip it. Never double up. Every dose matters: regular gaps let the pressure rise without any symptoms, so tell your eye doctor if you often miss doses.
Glaucoma drops control the disease but do not cure it, so they are usually needed long term. Laser or surgery can reduce or sometimes replace them, but many people still need some drops afterward. When people stop latanoprost, its pressure-lowering effect wears off, and on average pressure is back to its untreated level by about four weeks. Talk to your eye doctor before stopping or changing any drop, even if your eyes feel fine.
Laser and surgery exist partly because daily drops are hard to keep up. Selective laser trabeculoplasty (SLT) can replace or reduce drops for many people with open-angle glaucoma; in the LiGHT trial, about 3 in 4 people treated first with SLT needed no drops after three years. Two FDA-approved implants release medicine inside the eye for months: Durysta (bimatoprost, approved in 2020), which is given once per eye, and iDose TR (travoprost, approved in December 2023), whose label was updated in 2026 to allow a repeat implant no more than once a year, if checks show the cornea is still healthy. Minimally invasive glaucoma surgery, often done with cataract surgery, can also reduce the number of drops needed. Our guide to glaucoma surgery and laser compares these options.
Netra Restoration Therapy (NRT) at Netra Eye Institute does not lower eye pressure and cannot replace glaucoma drops, laser or surgery. Once glaucoma is medically controlled, some people still have trouble with scanning, reading or getting around because of field loss that has already happened. A functional assessment can look at those tasks and coordinate with low-vision care.
Learn about Netra Restoration Therapy, Netra Eye Institute’s approach and low-vision rehabilitation.
Anywhere from one to several, depending on the drops. Many people use a single prostaglandin drop once a day in the evening. Beta blockers are usually used twice a day, and brimonidine, dorzolamide and brinzolamide three times a day. Each dose is one drop in each affected eye.
Prostaglandin drops such as latanoprost, and netarsudil, are labeled for once-daily evening use. In a 1995 trial, evening doses of latanoprost lowered pressure slightly more than morning doses (35% against 31%). Not every glaucoma drop is taken at night; follow the times on your prescription.
There is no safe number of days to plan for. One prostaglandin dose works for about a day, and after people stop latanoprost, pressure is back to its untreated level by about four weeks on average. Gaps let pressure rise silently, so refill early and tell your eye doctor if you run out or cannot afford your drops.
No. Drops lower eye pressure to slow or stop further damage, but they do not cure glaucoma or restore vision already lost. Our guide to whether glaucoma can be cured explains what treatment can and cannot do.
There is no single best drop. Prostaglandins are often used first because one evening drop lowers pressure well. The right choice depends on how much pressure lowering you need, your other health conditions, side effects, cost and how many drops you can manage.
Tell your eye doctor. Redness is the most common side effect of prostaglandin drops and netarsudil. Options include switching drops, a preservative-free version, treating dry eye, or laser. Ask before using redness-relief drops from the pharmacy, because some are not suitable for people with narrow angles.
For a once-a-day evening drop, skip the missed dose and take the next one at the usual time. For drops used two or three times a day, use it when you remember unless the next dose is nearly due. Do not double up. Frequent gaps let eye pressure rise without symptoms. Phone reminders, linking drops to a daily habit and pharmacy refill reminders can help.
They can. The preservative benzalkonium chloride and some active ingredients irritate the eye’s surface, especially with long-term use. Preservative-free drops, lubricants and dry-eye treatment can help; ask your eye doctor before changing anything.
They lower eye pressure in one of two ways. Prostaglandins, netarsudil and pilocarpine help fluid drain out of the eye. Beta blockers, carbonic anhydrase inhibitors and brimonidine reduce how much fluid the eye makes; brimonidine also improves drainage.
Glaucoma eye drops work by lowering eye pressure, and trials show they slow vision loss. The best drop is one that reaches your target pressure, that your body tolerates and that you can use every day. If side effects, cost or the routine get in the way, tell your eye doctor: switching drops, combining them, or moving to laser or an implant usually works better than struggling on.
Medical Disclaimer: This article provides general education and is not medical advice, diagnosis or treatment. Glaucoma medicines must be prescribed and monitored by a licensed eye-care professional. Do not start, stop or change eye drops without advice. Sudden eye pain, redness, blurred vision or halos with headache, nausea or vomiting requires emergency care. NRT does not treat glaucoma and must never delay or replace pressure-lowering care.
