Anesthesia can affect eyesight after surgery, though the risk is low for most procedures. Estimates of vision loss following non-eye surgeries range from roughly one in 10,000 for general operations to as high as one in 500 for certain spine procedures. The causes span a wide range, from temporary corneal dryness that clears within a day to rare but devastating nerve damage that can leave a person permanently blind in one or both eyes. What makes this topic tricky is that the culprit is almost never the anesthetic drug alone; it is usually a combination of body positioning, blood loss, surgery duration, and the medications used alongside anesthesia.
How Common Is Postoperative Vision Loss?
Perioperative visual loss, or POVL, is an umbrella term for any decrease in vision that develops after surgery. One large review found that incidence rates for POVL after non-eye surgeries range from about 0.013 percent across all surgeries to around 0.2 percent after spine surgery specifically.1PubMed Central. Perioperative visual loss in ocular and nonocular surgery Another estimate places the range between 0.01 and 1 percent for non-eye procedures, with the upper end reflecting high-risk surgeries like long spinal fusions.2British Journal of Anaesthesia. Unilateral posterior ischaemic optic neuropathy after prolonged spinal surgery in the prone position These numbers are small in percentage terms, but given how many surgeries happen every year worldwide, the absolute number of affected patients is not negligible. And because vision loss can be life-altering, even a fraction of a percent matters.
Corneal Injuries During General Anesthesia
The most common eye-related problem after general anesthesia is not vision loss in the dramatic sense but a superficial corneal injury. When you are under general anesthesia, your blink reflex disappears and tear production drops. The eyelids may not close completely, leaving the corneal surface exposed to air, surgical drapes, or disinfectant solutions. This can cause drying, abrasion, or chemical irritation that you notice as scratchiness, blurred vision, or light sensitivity when you wake up.
A study comparing two methods of protecting the eyes during general anesthesia found that roughly 40 percent of eyes covered only with adhesive tape showed corneal injury immediately after surgery, compared with about 16 percent when a hydrogel patch was used instead.3PubMed Central. Corneal injury and its protection using hydro-gel patch during general anesthesia These numbers are striking, but the good news is that the discomfort typically resolves within 24 hours. The injuries are superficial, and the cornea heals quickly on its own or with lubricating drops. If you wake up from surgery and your eyes feel gritty or your vision is slightly blurry, this is the most likely explanation, and it almost always goes away.
Ischemic Optic Neuropathy
The condition that keeps anesthesiologists and surgeons up at night is ischemic optic neuropathy, or ION. This is damage to the optic nerve caused by reduced blood flow. It accounts for the majority of serious, permanent vision loss cases after non-eye surgery. The damage can occur at the front of the optic nerve (anterior ION) or the back (posterior ION), and the posterior form is more common after spine surgery.
The mechanism boils down to a squeeze on the optic nerve’s blood supply. During long surgeries performed face-down, gravity pushes fluid toward the head. The veins in and around the eye socket swell, and the pressure inside the eye rises. Because blood flow to the optic nerve depends on the difference between arterial pressure pushing blood in and venous or intraocular pressure resisting it, even a normal blood pressure reading can mask dangerously low perfusion at the nerve itself.4PubMed Central. Posterior ischemic optic neuropathy: Perioperative risk factors On top of that, significant blood loss during surgery lowers the oxygen-carrying capacity of the blood, and large volumes of IV fluids given to replace that loss can worsen tissue swelling around the eye.5PubMed Central. Ischemic optic neuropathy following spine surgery
An analysis of the American Society of Anesthesiologists’ visual loss registry looked at 93 spine surgery cases that resulted in vision loss. Eighty-three of those were ischemic optic neuropathy. The average anesthesia time was nearly 10 hours, the median blood loss was about 2 liters, and more than half of the patients lost vision in both eyes.6Anesthesiology. The American Society of Anesthesiologists Postoperative Visual Loss Registry: analysis of 93 spine surgery cases with postoperative visual loss The patients were not especially old or sick; the average age was around 50, and most were in otherwise reasonable health. That detail underscores something uncomfortable about this complication: it can happen to relatively healthy people undergoing elective procedures.
Currently, there is no proven treatment for perioperative ischemic optic neuropathy once it develops. Steroids, blood-pressure medications, and drugs that lower eye pressure have all been tried, but expert consensus holds that none of them reliably reverse the damage.7British Journal of Anaesthesia. Perioperative visual loss and anaesthesia That reality places the emphasis squarely on prevention.
Central Retinal Artery Occlusion From Surgical Positioning
Another mechanism for vision loss after surgery is blockage of the central retinal artery, which is the main blood vessel feeding the retina. This usually happens because of direct external pressure on the eye during surgery. If a patient is lying face-down and the headrest shifts or presses on the orbit, even briefly, it can compress the eye enough to cut off blood flow. One case report described a patient who developed retinal artery occlusion after cervical spine surgery in the prone position; after the patient was turned face-up, a visible pressure mark and redness were found over the affected eye.8PubMed Central. Perioperative central retinal artery occlusion after prone posterior cervical spine surgery treated with delayed hyperbaric oxygen therapy: a case report and targeted literature review
Horseshoe-shaped headrests, which cradle the face with openings for the eyes and mouth, are supposed to prevent this. But accidental shifts during hours-long surgery can bring the rim of the headrest into contact with the orbit.9PubMed. Central retinal artery occlusion after spinal surgery: Case report and literature review Unlike ischemic optic neuropathy, which involves the nerve behind the eye, retinal artery occlusion damages the retina itself. The classic sign on examination is a pale retina with a bright cherry-red spot at its center. Vision loss is typically severe and affects only the eye that was compressed. A literature review of case reports identified hundreds of such cases following non-eye surgery, making this one of the more commonly reported causes of serious perioperative visual loss.1PubMed Central. Perioperative visual loss in ocular and nonocular surgery
When the Brain Is the Problem
Not all postoperative vision loss originates in the eye. Cortical blindness occurs when the visual processing area at the back of the brain is damaged, typically by a stroke or reduced blood flow to that region. The eyes themselves are physically fine, the pupils still react to light, and a standard eye exam looks normal. The patient simply cannot see because the brain is not receiving or processing the visual signals.
Cortical blindness after surgery is associated with blood clots or emboli reaching the brain, severe drops in blood pressure, and low oxygen levels.10PubMed Central. Cortical blindness after complicated general anesthesia in urological surgery It can occur after cardiac surgery, where air or debris may enter the bloodstream, or after any procedure complicated by profound hypotension. One case report described bilateral cortical blindness from parieto-occipital infarction after general anesthesia, with the suspected causes including emboli, hypotension, and anemia.11Korean Journal of Anesthesiology. Bilateral Cortical Blindness Due to Parieto-Occipital Infarction after General Anesthesia: A case report When cortical blindness is suspected, brain imaging is essential to figure out what happened and whether any intervention might help.
Rising Eye Pressure and Acute Glaucoma
Intraocular pressure climbs during certain surgical positions, particularly the steep head-down tilt used in robotic-assisted abdominal surgeries. Studies of patients undergoing robotic prostatectomy in a steep 45-degree head-down position found that eye pressure roughly doubled during the procedure.12PubMed Central. Changes in intraocular pressure and optic nerve sheath diameter in patients undergoing robotic-assisted laparoscopic prostatectomy in steep 45° Trendelenburg position In most patients, this spike resolved after surgery without lasting visual damage. Temporary visual field changes have been observed after such procedures, but studies have not found lasting signs of nerve fiber damage or ischemia in the retina.13PubMed Central. The Impact of Steep Trendelenburg Position on Intraocular Pressure
A more dangerous situation arises when anesthesia triggers acute angle-closure glaucoma, a sudden and painful spike in eye pressure that can permanently damage the optic nerve if not treated quickly. Several drugs commonly used around surgery can contribute to this. Atropine and scopolamine dilate the pupil, which in a person with a narrow drainage angle can physically block the fluid outflow pathway inside the eye. Ephedrine, used to support blood pressure during anesthesia, has been implicated in triggering angle closure as well.14JAMA Ophthalmology. Acute Angle-Closure Glaucoma Associated With Surgical Anesthesia Recovery in a dark room and the psychological stress of surgery itself can further dilate the pupil, adding to the risk in susceptible individuals.15PubMed Central. Acute angle-closure glaucoma after general anesthesia for bone grafting People who have narrow angles and do not know it are especially vulnerable, and since angle-closure glaucoma is more common in older adults, farsighted individuals, and people of certain ethnic backgrounds, this risk is not evenly distributed.
Medications That Affect Vision Around Surgery
Some drugs used routinely in the perioperative period have direct effects on vision that are unrelated to nerve damage or blood flow. Scopolamine, a patch applied behind the ear to prevent nausea after surgery, is a well-known offender. Its anticholinergic properties cause the pupil to dilate and the focusing muscle inside the eye to relax, leading to blurred near vision that can persist for a day or two. A meta-analysis found that patients using transdermal scopolamine were more than three times as likely to report visual disturbances in the first one to two days after surgery compared with those given a placebo.16PubMed. Transdermal scopolamine for the prevention of postoperative nausea and vomiting: a systematic review and meta-analysis The blurriness is annoying but harmless and fades once the patch is removed or the drug wears off. Still, if nobody explains this to you beforehand, waking up with blurred vision after surgery can be frightening.
A more dangerous drug interaction involves nitrous oxide, sometimes used as part of general anesthesia. If you have a gas bubble inside your eye from a recent retinal surgery, nitrous oxide can diffuse into that bubble and expand it rapidly. The resulting pressure spike can be severe enough to cut off blood flow to the retina entirely. Patients and their families are strongly advised to inform any anesthesia team about the presence of an intraocular gas bubble, and some experts recommend that these patients wear a medical alert bracelet until the gas has fully absorbed, which can take several months.17PubMed. Complications of general anesthesia using nitrous oxide in eyes with preexisting gas bubbles
Eye Blocks for Ophthalmic Surgery
When anesthesia is injected directly around the eye for cataract or other ocular procedures, the local anesthetic itself can temporarily block the optic nerve. Patients given retrobulbar anesthesia with lidocaine have experienced transient loss of vision in the injected eye, with measurable changes in the nerve’s electrical signals that returned to normal as the drug wore off.18Ophthalmic Surgery, Lasers and Imaging Retina. Temporary Conduction Block of Optic Nerve After Retrobulbar Anesthesia This is expected and not a sign of damage. More concerning are the rare structural complications of eye blocks: orbital hemorrhage, which happened in about 0.74 percent of cases in one large study of over 16,000 peribulbar blocks, and globe perforation, which occurred in fewer than one in 16,000.19Journal of Cataract & Refractive Surgery. Efficacy and complication rate of 16,224 consecutive peribulbar blocks: A prospective multicenter study These are serious complications, but they are not caused by anesthesia acting on the visual system so much as by the needle used to deliver it.
What to Do If Your Vision Changes After Surgery
If you notice any change in your vision after waking up from surgery, say something immediately. Do not assume it is residual grogginess from the anesthetic. The current expert recommendation is that a patient’s vision should be checked as soon as they are alert enough to cooperate, particularly after high-risk procedures like spine or cardiac surgery. If there is any concern about vision loss, an urgent eye consultation should be obtained right away.7British Journal of Anaesthesia. Perioperative visual loss and anaesthesia When the ophthalmologist finds no obvious eye-related cause, brain imaging should follow promptly to rule out stroke or other central causes.20PubMed Central. Perioperative visual loss after nonocular surgeries
Speed matters because some causes, like retinal artery blockage, have a narrow treatment window. Others, like ischemic optic neuropathy, currently have no effective treatment, but early evaluation at least establishes a baseline and rules out treatable conditions. For milder complaints like blurriness or dry-eye symptoms, the clinical team can often reassure you on the spot and provide lubricating drops or remove a scopolamine patch if one was placed.
Who Faces the Highest Risk?
Not every surgery carries the same visual risk. The procedures most strongly linked to serious postoperative vision loss are prolonged spine surgeries performed in the prone position, followed by cardiac bypass procedures. In spine cases, the combination of face-down positioning, lengthy operative times, heavy blood loss, low blood pressure, and massive fluid replacement creates a perfect storm for optic nerve ischemia.21PubMed Central. Postoperative visual loss associated with spine surgery One study of seven patients who developed posterior ischemic optic neuropathy found that all had experienced significant blood loss (ranging from 2 to 16 liters) and drops in blood pressure during their operations.22PubMed. Perioperative risk factors for posterior ischemic optic neuropathy
Patient-level factors also play a role. Obesity has been associated with cortical blindness after surgery, possibly because it worsens venous congestion in the prone position. Preexisting vascular disease, diabetes, and anemia may make the optic nerve more vulnerable to drops in perfusion that a healthier nerve could tolerate. People with undiagnosed narrow-angle anatomy in their eyes are at risk for acute glaucoma from the mydriatic drugs used perioperatively. And anyone who has recently had retinal surgery involving a gas bubble faces a unique hazard if nitrous oxide is used. The American Society of Anesthesiologists published a practice advisory specifically for perioperative visual loss in spine surgery, reflecting how seriously the profession takes these risks in that setting.23PubMed Central. Practice Advisory for Perioperative Visual Loss Associated with Spine Surgery 2019
Why This Complication Remains Poorly Understood
Given the severity of the outcome, you might expect a large body of research on perioperative vision loss. In practice, the evidence base is thinner than it should be, and one reason is legal. Many cases end up in malpractice litigation, which means the clinical details become sealed in legal proceedings rather than published in medical journals. A review of this problem noted that malpractice claims create a barrier to studying POVL because case information is not made publicly available.24PubMed Central. Revisiting Postoperative Vision Loss following Non-Ocular Surgery: A Short Review of Etiology and Legal Considerations Interestingly, when these claims do go to trial or settlement, courts have tended to side with the defendants, suggesting that the complication is widely viewed as unpreventable under current knowledge rather than negligent.25PubMed. Malpractice outcomes of perioperative ischaemic optic neuropathy after nonocular surgery
This creates a frustrating cycle. Fewer published cases means less data to identify risk factors, build prediction tools, or test preventive strategies. The ASA’s visual loss registry was created partly to break this cycle by collecting standardized information outside the litigation process, but participation is voluntary, and the registry captures only a fraction of cases. If you are facing a high-risk surgery and your surgeon or anesthesiologist brings up the possibility of vision loss during the consent conversation, that transparency is actually a sign that the team is following best practices. The push within anesthesiology is to discuss this risk openly with patients heading into prolonged prone or cardiac procedures, both because it is the right thing to do and because informed consent may itself reduce the adversarial dynamic that keeps case data locked away.