Diving With Glaucoma: Pressure, Medication, and Clearance

Introduction

If you have glaucoma and you dive, you have probably asked yourself whether it is safe to keep diving. Maybe you were recently diagnosed and are wondering if your diving days are over. Or perhaps you have been managing the condition for years and want to make sure you are not missing something important.

The short answer is that many divers with glaucoma can continue diving safely, but it takes careful management. Diving with glaucoma is not automatically disqualifying, but it requires stable eye pressure, proper medication timing, and thorough medical clearance. This article breaks down exactly what you need to know, what you need to do, and what can go wrong if you are not careful.

I have worked with dozens of divers who manage glaucoma. The ones who do it well treat it like any other medical condition that affects diving: they plan ahead, they stay on top of their numbers, and they do not take shortcuts. This guide is designed to help you do the same.

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Understanding Glaucoma and Eye Pressure

Glaucoma is not a single disease. It is a group of conditions that damage the optic nerve, usually because of elevated intraocular pressure (IOP). Think of the eye as a fluid-filled chamber. When the drainage system does not work properly, pressure builds up. Over time, that pressure can damage the nerve fibers that send visual information to your brain.

The key number here is your intraocular pressure. Normal IOP is typically between 10 and 21 mmHg. In glaucoma, that number can creep higher, sometimes much higher, depending on the type and how well it is controlled.

So how does this connect to diving? During descent, ambient pressure increases. That external pressure compresses the gases inside your body, including those inside your eye. For most people with healthy eyes, this causes a temporary drop in IOP during the dive and a return to normal on ascent. For a diver with glaucoma, the concern is whether these pressure changes can trigger a spike in IOP or worsen existing damage.

There is also the question of bubble formation. Decompression sickness can affect any part of the body, including the eye. If you have compromised optic nerve tissue, you may be more vulnerable to damage from even small bubbles. This is theoretical but worth understanding when you assess your personal risk.

Can You Dive With Glaucoma? Key Medical Considerations

The straightforward answer is yes, many divers with well-controlled, stable glaucoma can dive. But there are several factors that determine whether you are a good candidate.

Stability of the condition is the most important factor. If your IOP has been consistently within a safe range for at least six months, and your ophthalmologist confirms there has been no progression of optic nerve damage, you are in a much better position than someone whose numbers fluctuate or whose vision is worsening.

The degree of optic nerve damage matters. If you have advanced damage with significant visual field loss, the risks increase. You are essentially diving with a compromised system, and any additional insult, even a minor one, could have disproportionate consequences.

Other eye problems complicate things. If you also have cataracts, retinal issues, or a history of eye surgery, your risk profile changes. For example, someone who has had a vitrectomy or a scleral buckle procedure may have different pressure dynamics in the eye. The same goes for someone with a history of retinal detachment.

Overall health is a factor too. Glaucoma often coexists with conditions like hypertension, diabetes, and cardiovascular disease. These conditions independently affect diving fitness and can interact with glaucoma medications in ways that matter underwater.

This is why medical clearance is not optional. It is the single most important step you can take. Do not rely on a general practitioner who has never cleared a diver. See someone who understands dive medicine and eye health.

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How Glaucoma Medications Affect Diving Fitness

Most glaucoma treatments work by either reducing the production of fluid in the eye or improving its drainage. These are usually eye drops, but some oral medications are also used. Each class of medication comes with side effects that matter for diving.

Prostaglandin analogs are the most common first-line treatment. They work well and have few systemic side effects. For most divers, these are the safest option. The main downside is that they can cause eye redness, irritation, and changes in eyelash growth, but none of these affect diving fitness directly.

Beta-blockers like timolol are another common class. These can lower heart rate, reduce exercise tolerance, and cause fatigue. If you are on a beta-blocker, your heart rate response during a dive may be blunted. This is not a dealbreaker for most recreational divers, but it matters if you are prone to heavy exertion, cold water, or currents. Travelers who need a simple way to monitor their heart rate during dives may find a dive watch with heart rate monitoring helpful for tracking exertion.

Carbonic anhydrase inhibitors like acetazolamide are used less often but deserve special attention. These are diuretics. They reduce fluid production in the eye, but they also affect your body’s overall fluid balance and can cause electrolyte disturbances. Dehydration is already a risk for divers. Combining a diuretic with the dry air of a dive boat and the physical demands of diving is a recipe for trouble. If you are on this class of medication, hydration planning is not optional. A simple way to stay on top of fluid intake is using a hydration pack for scuba diving, which allows you to sip water throughout the day.

Timing matters. Most glaucoma medications are prescribed for daily use, often once or twice a day. If you take a dose in the morning before a dive, you should be fine. But if you miss a dose because of travel, time zone changes, or just forgetfulness, do not double up. Skipping a single dose is usually safer than risking side effects from an extra dose. Carry your medication with you on the boat and set an alarm if you need to.

A word on changes: do not switch medications or change dosages right before a dive trip. Your body needs time to adjust. If your ophthalmologist wants to try a new drug, do it at least a month before your trip, not the week before you fly to Cozumel.

The Role of Eye Pressure Monitoring in Diving

Your IOP is the single most objective data point you and your doctor will use to assess your fitness to dive. It is measured using tonometry, a simple in-office test that takes about 30 seconds.

Most diving medicine guidelines consider an IOP of 22 mmHg or below as acceptable for diving, provided the pressure is stable and there is no evidence of progressive optic nerve damage. Some physicians use a more conservative cutoff of 20 mmHg. The exact number matters less than the trend. If your pressure has been creeping up over the last two years, that is more concerning than a single reading of 21 mmHg that has been unchanged for years.

One thing many divers do not consider is how dehydration affects IOP. When you are dehydrated, your eye pressure can drop temporarily. This might sound like a good thing, but it means your pressure reading on land may not reflect what happens underwater. More importantly, as you rehydrate, your pressure can rebound. If you have been drinking heavily the night before a dive or skipping water during a day of multiple dives, your IOP could be unpredictable.

Get a recent checkup before you book any dive trip. Ideally, that checkup should be within three months of your departure. If your pressure is stable and your optic nerves look good, you have a solid baseline to work from.

Medical Clearance for Diving With Glaucoma

Getting proper medical clearance is not complicated, but it requires some preparation. Here is what you should do.

First, schedule an appointment with your ophthalmologist. Bring a copy of the standard dive medical questionnaire. Many divers assume this form is just for their GP, but it is better to have your eye doctor fill out the relevant sections directly. If your ophthalmologist has never dealt with a diver before, it helps to come prepared with your own knowledge.

Second, ask specific questions. Do not just ask ‘can I dive?’ Instead, ask:

• Is my intraocular pressure stable within a safe range?
• Has there been any progression of optic nerve damage in the last year?
• Do I have any other eye conditions that could affect diving?
• Are my medications safe for use with diving?
• Do I need any adjustments to my medication schedule?

Third, ask for a letter. A signed letter from your ophthalmologist stating that your glaucoma is stable, well-controlled, and that you are fit for recreational scuba diving is worth its weight in gold. Some dive operators, liveaboards, and insurance companies will ask for this. Having it in hand saves you from last-minute cancellations.

The medical clearance process is not designed to stop you from diving. It is designed to make sure you dive safely. The vast majority of divers with stable glaucoma who go through this process come out with a green light.

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Common Mistakes Divers With Glaucoma Make

After working with hundreds of divers over the years, I have seen the same mistakes come up again and again. Here are the ones to avoid.

Mistake one: diving without a recent eye exam. You would not jump into the ocean without checking your tank pressure. Do not dive without knowing your current IOP. A six-month-old reading is not enough. Things change. Get checked within three months of your trip.

Mistake two: using expired medications or running out mid-trip. Overseas, the same medication may be sold under a different name or may not be available at all. Always pack more than you need. Carry a written prescription. And check the expiration date before you leave.

Mistake three: ignoring symptoms during a dive. If you feel eye pain, see new floaters, or notice blurred vision during a dive, end the dive. This is not a test of toughness. These symptoms could mean your intraocular pressure is changing in a way that is not safe. Surface, signal your buddy, and get to a doctor if it does not resolve quickly.

Mistake four: not telling your dive buddy or instructor. You do not need to announce your medical history to everyone on the boat. But your buddy and the dive leader should know you have a condition that could cause vision changes underwater. If something goes wrong, they need to understand why you might not see clearly or why you are surfacing quickly.

Mistake five: assuming stable glaucoma means zero risk. Stable glaucoma is not the same as no glaucoma. You still need to be cautious about dehydration, medication timing, and pressure changes. Do not get complacent because your last eye exam was good.

Worst-Case Scenario: Can Diving Worsen Glaucoma?

This is the question that keeps many divers with glaucoma awake at night. Let me be direct: there is no strong evidence that recreational scuba diving worsens stable, well-controlled glaucoma. But there are theoretical risks, and for some individuals, those risks become real.

Barotrauma is the most straightforward concern. If your eye has any weak points, such as a recent surgical incision or a thin cornea, the pressure changes during diving could cause local damage. This is rare but possible.

Vascular changes are another area of concern. The optic nerve relies on a steady blood supply. During a dive, your blood vessels constrict in response to cold, immersion, and gas loading. If your optic nerve is already compromised, it may not tolerate even minor reductions in blood flow. This is theoretical, but it is the reason why divers with advanced glaucoma are usually advised not to dive.

Rapid pressure shifts during ascent could theoretically cause a spike in IOP. Some research has shown that IOP can increase slightly on ascent, possibly due to gas expansion in the eye. In a healthy eye, this is harmless. In an eye with compromised drainage, it could be problematic.

The honest answer is that for most divers with stable, mild to moderate glaucoma, the benefits of diving outweigh the risks. But for anyone with advanced damage, fluctuating pressures, or coexisting eye disease, the risk-benefit ratio shifts. This is a conversation to have with your ophthalmologist, not one to guess about on a dive forum.

Medication and Travel: What To Pack and Plan

Traveling with glaucoma medication requires more than throwing a bottle in your toiletry bag. Here is a practical packing list.

Carry your medications in your carry-on luggage. Checked bags get lost. If your drops are in a checked bag that ends up in Paris while you are in the Maldives, you have a problem. Always carry at least a week’s supply on your person.

Bring a written prescription. Some countries have strict regulations about importing medications. Having a copy of your prescription in English and the local language can save you at a customs checkpoint. It also helps if you lose your medication and need to buy a replacement.

Pack more than you need. If your trip is seven days, bring enough for ten. If you are on a liveaboard with no access to a pharmacy, bring enough for the entire trip plus a few extra days. Do not count on being able to buy the same medication at your destination.

Check storage requirements. Some prostaglandin analogs need to be refrigerated. Others can be stored at room temperature. If you are traveling somewhere hot, find out if your medication can handle the heat. A cooling case or an insulated bag designed for medication can be a worthwhile investment. Travelers who need to keep their drops at the right temperature may benefit from an insulated medication travel case. These are small, affordable, and can make the difference between effective medication and spoiled drops.

Consider a small medical travel kit. A zippered pouch that holds your eye drops, a backup bottle, a written prescription, and a list of emergency contacts is easy to pack and easy to find when you need it. Some travel medical kits on Amazon include compartments for bottles and syringes, which works well for multiple drop bottles.

When To Skip the Dive: Red Flags You Should Not Ignore

Some days, the right call is to stay on the boat. Here is when you should make that call.

Acute eye pain. If your eye hurts, something is wrong. Do not dive. Do not even think about diving. Get it checked.

Blurred vision. If your vision is blurry and it is not normal for you, do not dive. This can be a sign of elevated IOP, corneal edema, or something else entirely. None of those are safe underwater.

Recent changes in vision. If you noticed new floaters, flashes of light, or a shadow in your visual field in the last few days, skip the dive. These could signal retinal issues, which are a hard contraindication to diving.

Elevated IOP on your last checkup. If your most recent eye exam showed a pressure above 22 mmHg or a significant increase from your baseline, do not dive until you have spoken to your ophthalmologist. Do not assume it is a fluke.

Feeling unwell. If you are tired, dehydrated, hung over, or just off, your IOP may be affected. Do not push it. There will be another dive tomorrow.

Alternatives and Adjustments: Still Enjoy the Water

If your ophthalmologist recommends against scuba diving, it does not mean you have to stay out of the water entirely. There are options.

Snorkeling is low-risk for glaucoma. You are at the surface, so there are no significant pressure changes. The only caveat is that if you are on a medication that causes fatigue or dizziness, be cautious about swimming in rough conditions or strong currents. But for most people, snorkeling is perfectly fine. Travelers who want to enjoy the water while avoiding pressure changes may find a prescription snorkel mask useful for clear vision without having to wear contact lenses.

Freediving requires more caution. Breath-hold diving involves rapid pressure changes on descent and ascent, and the Valsalva maneuver some freedivers use during equalization can transiently spike IOP. If you want to freedive, get specific clearance from your eye doctor. Shallow freediving, staying under ten meters, is usually lower risk than deep freediving, but you should still discuss it.

Scuba diving at very shallow depths, such as guided training dives or reef dives under 12 meters, may be an option if your condition is very stable and you have clearance. Some dive operators will require a medical waiver or a doctor’s note. Be upfront with the shop. They have seen this before, and they will work with you if you are honest about your situation.

The point is that the ocean is not off-limits. You just need to find the right way to enjoy it.

Final Checklist Before Booking Your Dive Trip

Before you book anything, run through this list.

• Visit your ophthalmologist within the last three months and get a current IOP reading.
• Obtain a signed letter of clearance specifically for scuba diving.
• Review your medication plan with your doctor and adjust timing if needed.
• Pack enough medication for the entire trip plus extra, stored in your carry-on.
• Inform the dive shop or operator that you have glaucoma and that you have medical clearance.
• Check your travel insurance policy. Make sure it covers pre-existing medical conditions. Some policies exclude them. Diving-specific insurance like DAN or Dive Assure usually offers coverage for stable conditions with a doctor’s note. If you need to buy a policy, consider one that includes trip cancellation and medical evacuation.
• Do a self-assessment on the morning of every dive. If anything feels off, stay out.

Need a Dive Medical Consultation?

If you are uncertain about your specific situation, do not guess. A dive medical consultation is the safest way to get a clear, personalized answer.

At 1st Contact Travel Clinic, our specialists understand both diving physiology and eye health. We can review your medical history, your current eye exam results, and your medication plan to give you a straightforward recommendation. We do not just say yes or no. We explain why, and we help you plan a safe dive trip if the answer is yes.

Book a consultation online or stop into any of our clinic locations. It takes less than an hour, and you will leave with the confidence to enjoy your next dive safely.