Florida Clinical Trial Finds Oral CBD May Rival Opioids for Pain After Eye Surgery

A new clinical trial conducted by University of Florida researchers suggests that a low-THC, full-spectrum CBD formulation may control acute pain following laser eye surgery as effectively as a commonly prescribed opioid medication.

Published in the Journal of Cataract & Refractive Surgery, the study compared oral CBD with a combination of codeine and acetaminophen in patients recovering from photorefractive keratectomy, better known as PRK.

The findings add to a growing body of evidence suggesting that cannabinoids may eventually help some patients manage postoperative pain while reducing their exposure to prescription opioids.

CBD Versus Codeine After PRK Eye Surgery

PRK is a laser procedure used to correct nearsightedness and other refractive vision problems. Although it can offer advantages over LASIK for certain patients, the recovery period can involve significant eye pain and discomfort while the surface of the cornea heals.

Doctors may prescribe oral opioid medications—often combined with acetaminophen—to control that pain. These medications can be effective, but they also carry risks that include nausea, constipation, sedation, respiratory depression, physical dependence and misuse.

Researchers affiliated with the University of Florida Department of Ophthalmology wanted to determine whether oral CBD could provide comparable pain relief without relying on a conventional opioid regimen.

The prospective, randomized clinical trial enrolled 35 adults undergoing PRK in both eyes. Each participant received surgery on the eyes separately. Following one procedure, the patient received CBD; following the other, the same patient received codeine-acetaminophen.

This crossover design allowed every participant to serve as their own control, helping researchers compare the two treatments while limiting the influence of individual differences in pain sensitivity.

What Did the Clinical Trial Find?

For the CBD portion of the study, participants took a 50-milligram full-spectrum CBD softgel twice daily. The formulation contained less than 0.3% THC.

For the opioid portion, participants received codeine-acetaminophen containing 30 milligrams of codeine and 300 milligrams of acetaminophen every four hours, equivalent to approximately 18 morphine milligram equivalents per day.

Participants recorded their pain on a 10-point scale during recovery. Pain generally peaked on the second day following surgery, but researchers found no statistically significant difference between the average or maximum pain scores reported under the two treatments.

In other words, the CBD formulation produced pain control that researchers determined was non-inferior to codeine-acetaminophen.

The study also found:

• Visual acuity improved significantly following both treatments.

• Recovery outcomes were similar between the CBD and opioid portions of the trial.

• Other reported symptoms and quality-of-life measurements were generally equivalent.

• Some participants reported mild changes in sensorium when CBD was used following their first eye surgery, suggesting a possible first-exposure effect.

• Researchers characterized the CBD formulation as having minimal side effects overall.

The authors concluded that twice-daily use of the low-THC CBD product offered safe pain control comparable to the standard opioid regimen used in the study.

The findings were first highlighted by National NORML in its August 13, 2026 report.

Why This Study Matters

The significance of this trial extends beyond eye surgery.

One of the medical community’s most difficult challenges is finding reliable ways to treat acute pain without unnecessarily exposing patients to opioids. Even a legitimate, short-term prescription can produce unwanted side effects, and unused pills may remain in homes where they can be diverted or misused.

An effective non-opioid option could potentially reduce the number of opioid prescriptions written after certain procedures.

This study does not prove that CBD can replace opioids following every type of surgery. However, it provides a meaningful clinical signal in a controlled setting where CBD was directly compared with an established opioid medication.

Unlike surveys based on patients’ recollections or observational studies that cannot easily establish cause and effect, this was a randomized, self-controlled clinical trial. That makes the results more valuable, although the modest number of participants means that larger studies are still needed.

The study was registered with the federal government as ClinicalTrials.gov study NCT05477875.

Not Every CBD Product Is the Same

Consumers should not interpret these findings as evidence that any CBD product purchased online or at a gas station can safely replace prescribed pain medication.

Researchers tested a specific full-spectrum, plant-derived formulation at a specific dose. The product contained primarily CBD but also included trace amounts of THC below the federal hemp threshold.

Commercial CBD products can differ significantly in their cannabinoid concentrations, purity, ingredients and laboratory-testing standards. Some products may contain less CBD than advertised, while others may contain unexpected THC, contaminants or undisclosed compounds.

The trial therefore supports further investigation of this particular kind of controlled CBD treatment—not the assumption that every retail hemp product will produce the same result.

Patients should also understand that CBD can interact with certain prescription medications because it may affect how drugs are metabolized by the liver. Anyone considering CBD around the time of surgery should discuss it with their surgeon, ophthalmologist or pharmacist rather than attempting to create an unsupervised treatment plan.

CBD Is Not Yet an FDA-Approved Postoperative Pain Medication

Despite the promising findings, CBD is not currently approved by the U.S. Food and Drug Administration as a treatment for postoperative pain.

The FDA has approved one purified CBD medication for certain seizure disorders, but that approval does not automatically apply to pain, surgical recovery or commercially available CBD products.

More research will be necessary to answer several important questions:

• What is the most effective CBD dose for acute pain?

• Which types of surgery might respond to cannabinoid-based treatments?

• Would CBD work as well in larger and more diverse patient populations?

• How does full-spectrum CBD compare with purified CBD isolate?

• Could CBD be combined with other non-opioid medications as part of a broader pain-control plan?

• What interactions or side effects might emerge in patients with more complicated medical histories?

These questions are precisely why federal barriers to cannabis research remain so counterproductive. Patients, doctors and policymakers need evidence developed through carefully designed clinical trials—not assumptions shaped by either cannabis stigma or exaggerated marketing.

Another Reason to Expand Cannabinoid Research

For decades, federal cannabis policy has treated the plant primarily as a criminal-justice issue. Research like this demonstrates why cannabis and its compounds must also be evaluated as matters of medicine, science and public health.

The responsible response is neither to claim that CBD is a miracle drug nor to dismiss its potential because it comes from cannabis.

The responsible response is to conduct larger trials, establish consistent product standards and allow physicians to make decisions based on evidence.

A 35-person clinical trial will not rewrite postoperative medicine overnight. But when a plant-derived CBD formulation produces pain relief comparable to codeine-acetaminophen in a randomized trial, the result deserves serious attention.

For patients recovering from surgery—and for a country still struggling with the consequences of opioid overprescribing—that possibility is worth investigating.

Frequently Asked Questions

Can CBD replace opioids after eye surgery?

This study found that a specific low-THC CBD formulation provided pain control comparable to codeine-acetaminophen following PRK. It does not establish CBD as a universal replacement for opioids or other postoperative medications.

How much CBD did participants take?

Participants received 50 milligrams of full-spectrum oral CBD twice daily during the CBD portion of the trial.

Did the CBD contain THC?

Yes. Researchers used a full-spectrum product containing less than 0.3% THC. The results should not automatically be applied to CBD isolate or unrelated retail formulations.

Was CBD more effective than codeine?

No. The study found no significant difference in pain control. Researchers concluded that CBD was non-inferior, meaning it performed comparably within the parameters of the trial.

Should patients take CBD before or after surgery?

Patients should consult their doctor first. CBD can interact with medications, and surgeons need to know about supplements or cannabinoid products being used before and after a procedure.

This article is for educational and informational purposes only and is not medical advice. Do not discontinue or replace a prescribed medication without consulting a qualified healthcare professional.