Eyeball pain spans a wide spectrum, from the gritty ache of a tired, dry eye after a long day at a screen to the sudden, severe throbbing of an ophthalmologic emergency like acute angle-closure glaucoma. The eye is one of the most densely nerve-supplied organs in the body, which means even a tiny scratch on the cornea can produce outsized discomfort. Most causes of eye pain are benign and resolve on their own or with simple treatment, but a handful demand urgent medical attention because they threaten your vision. Understanding the pattern of your pain, what came before it, and what other symptoms ride alongside it will help you figure out where your situation falls.
Why the Eye Is So Sensitive to Pain
Your cornea, the clear dome at the front of the eye, is packed with sensory nerve fibers. These fibers come mainly from the ophthalmic branch of the trigeminal nerve, which also supplies sensation to the eyelids and the thin membrane lining the inside of the lids (the conjunctiva).1Wiley Online Library. Role of corneal nerves in ocular surface homeostasis and disease This dense nerve network is what makes a stray eyelash feel so much worse than a splinter in your finger, even though the splinter is objectively a bigger injury. The same wiring explains why so many different conditions produce overlapping symptoms: burning, stinging, aching, or sharp stabbing pain can all come from irritation of the same nerve pathways, just at different depths or intensities.
Common Surface Causes
Dry Eye and Neuropathic Pain
Dry eye is probably the single most frequent reason people experience a chronic aching or burning sensation in their eyes. It starts simply enough: your tear film breaks down faster than it should, leaving the corneal surface exposed. But researchers have found that in some people, the story gets more complicated. Repeated irritation of the sensory nerves on the eye’s surface can trigger changes in how those nerves process signals, shifting from a straightforward “something is dry” message into a chronic pain state that persists even when the surface looks relatively healthy.2Oxford University Press. Burning Eye Syndrome: Do Neuropathic Pain Mechanisms Underlie Chronic Dry Eye? This is why some dry-eye sufferers keep reporting pain despite normal-looking tear tests. Their pain has become partly neuropathic, meaning the nerves themselves are misfiring. If you have been treated for dry eye with artificial tears and still feel like your eyes are burning, this mechanism is worth discussing with your eye doctor.
Digital Eye Strain
Spending long hours on a screen does not damage your eyes in any permanent structural sense, but it can make them ache. When you focus on something close, the muscles inside your eye that control the lens have to maintain steady contraction. Prolonged screen time can worsen pre-existing issues with how your eyes converge and focus, producing headaches, blurry vision, and a dull pain around or behind the eyes.3PubMed Central. A Review of Digital Eye Strain: Binocular Vision Anomalies, Ocular Surface Changes, and the Need for Objective Assessment You also blink less while staring at a screen, which circles back to dry eye. The classic advice of looking at something 20 feet away for 20 seconds every 20 minutes is not based on rigorous trials, but it does give the focusing muscles a break and prompts you to blink.
Corneal Abrasions and Foreign Bodies
A scratch on the cornea, or a small particle trapped under the eyelid, produces a sharp, stabbing pain that typically gets worse when you blink. You might feel like there is something in your eye even after you have flushed it out, because the scratch itself continues to stimulate pain receptors. Most small abrasions heal within a day or two as the corneal surface regenerates quickly. Deeper or larger scratches, or ones caused by organic material like a tree branch, carry a higher risk of infection and may need antibiotic drops and close follow-up.
Contact Lens Complications
Contact lenses sit directly on the cornea, and if you sleep in them, skip cleaning, or use expired solution, you create a warm, moist environment where bacteria and other organisms thrive. Corneal ulcers caused by infection are a serious concern for lens wearers worldwide.4Europe PMC. Contact lens related corneal ulcer These ulcers feel like intense, unrelenting eye pain accompanied by redness, light sensitivity, and sometimes a visible white spot on the cornea.
What makes contact-lens infections particularly tricky is that they are often polymicrobial, meaning more than one type of organism is involved. In one well-documented case, a patient’s corneal ulcer grew both Pseudomonas bacteria and tested positive for Acanthamoeba, a free-living amoeba found in tap water.5PubMed Central. Polymicrobial Infection of the Cornea Due to Contact Lens Wear Mixed infections like these are harder to treat and tend to relapse despite adequate therapy. The practical takeaway: never rinse your lenses or case with tap water, never sleep in lenses not designed for overnight wear, and if your eye suddenly becomes red and painful while you are wearing contacts, take them out immediately and see an eye doctor that day, not next week.
Acute Angle-Closure Glaucoma
This is the eye-pain emergency that eye doctors worry about most, because delayed treatment can cause permanent vision loss within hours. Acute angle-closure glaucoma happens when the drainage channel inside the eye gets physically blocked, causing a rapid spike in the pressure of the fluid inside the eye.6CrossRef. Acute Angle-Closure Glaucoma Developing During the Treatment of an Asthma Attack: A Case Report The pain is severe and comes on suddenly, often in one eye, and is typically accompanied by nausea, vomiting, seeing halos around lights, and a visibly red eye. The eye may feel rock-hard to the touch compared to the other side.
This condition is more common in people who are farsighted, older adults, and those of East Asian descent, because certain eye anatomies have a naturally narrower drainage angle. Some medications, including certain antihistamines, decongestants, and drugs used during asthma attacks, can trigger an episode by dilating the pupil and pushing the iris forward into the drainage channel. If you experience sudden severe eye pain with blurred vision and nausea, go to an emergency room. This is not a “wait and see” situation.
Pain Behind the Eye
Optic Neuritis
Pain that feels like it is deep behind the eyeball, especially pain that worsens when you move your eyes, is the hallmark of optic neuritis. This is inflammation of the optic nerve, and it typically shows up as one-sided, subacute, painful vision loss without other neurological symptoms at first.7Europe PMC. Optic neuritis as an early sign of multiple sclerosis Vision loss in optic neuritis usually develops over days, not minutes, and colors may look washed out in the affected eye. This condition is well known as an early sign of multiple sclerosis, though it also occurs in isolation and from other causes. Anyone with new eye pain that worsens with eye movement and is accompanied by vision changes should be evaluated promptly. An MRI and sometimes a lumbar puncture help determine whether the inflammation is an isolated event or part of a broader neurological condition.
Orbital Infections and Inflammation
The orbit is the bony socket that houses the eye, and infections here produce deep, aching pain along with swelling of the eyelids, restricted eye movement, and sometimes fever. Orbital cellulitis usually starts as a sinus infection that spreads backward into the tissues around the eye. It is more common in children and is treated as a medical emergency because the infection can spread to the brain. Inflammatory conditions like scleritis, where the tough white outer coat of the eye becomes inflamed, also produce a boring, deep pain that can wake you at night. Scleritis is less common than the milder episcleritis but is more likely to be linked to underlying autoimmune conditions.
When the Problem Is Not Actually Your Eye
The trigeminal nerve that supplies sensation to the eye also covers a broad territory across the face, sinuses, and scalp. This shared wiring means pain originating elsewhere can feel like it is coming from the eyeball. Sinus infections commonly cause a pressure-type ache behind or around the eyes, especially when you bend forward. Tension headaches and migraines can localize to one eye.
One particularly dramatic example is cluster headache, which causes excruciating pain around or behind one eye, often with tearing, a red eye, and eyelid drooping on the affected side. Because the eye symptoms are so prominent, people with cluster headaches sometimes spend years consulting ophthalmologists for what turns out to be a primary headache disorder.8Europe PMC. Masquerades of cluster headache If your eye pain comes in intense episodes lasting 15 minutes to three hours, always on the same side, and tends to wake you from sleep at the same time of night, consider bringing this pattern to your doctor’s attention rather than returning to the eye clinic.
Autoimmune and Systemic Disease Connections
Eye pain is sometimes the first clue that something broader is happening in the body. Rheumatoid arthritis, for example, carries a well-established list of eye complications including dry eye, episcleritis, scleritis, and corneal changes.9Europe PMC. Ocular manifestation of rheumatoid arthritis-different forms and frequency Other autoimmune conditions linked to eye inflammation include lupus, ankylosing spondylitis, and inflammatory bowel disease. Uveitis, inflammation of the eye’s middle layer, is a particularly common crossover: it causes a dull ache with light sensitivity and floaters, and about half of uveitis cases are associated with systemic inflammatory or infectious diseases.
If you keep getting episodes of red, painful eyes and standard treatments are not working, your eye doctor may order blood tests looking for inflammatory markers, autoimmune antibodies, or signs of infection like tuberculosis or syphilis. Recurrent or bilateral uveitis in a young person is especially suspicious for an underlying systemic condition. Treating just the eye inflammation without addressing the root cause leads to repeated flare-ups and progressive damage.
Chemical Burns
Getting a chemical splash in the eye produces immediate, searing pain. But the severity of the injury depends heavily on the type of chemical. Alkali substances like oven cleaner, lye, or cement dust are lipophilic, meaning they dissolve through cell membranes and penetrate rapidly through the cornea into the interior of the eye, causing severe damage to deeper structures.10Europe PMC. Chemical burns acid or alkali, what’s the difference? Acids, by contrast, cause the surface proteins to clump together, which ironically acts as a barrier that limits how deep the acid can reach. This is why an alkali burn is generally considered more dangerous than an acid burn of similar concentration.
The critical first step for any chemical splash is copious irrigation with water or saline, starting immediately and continuing for at least 15 to 30 minutes before doing anything else, including driving to the hospital. The instinct to rush to the emergency room without irrigating first wastes valuable minutes. If the chemical was alkali-based, the eye still needs urgent professional evaluation after irrigation, even if the pain has improved.
Post-Surgical Eye Pain
Eye surgery, including LASIK and cataract removal, involves cutting through corneal nerves. Most patients experience at least mild discomfort after LASIK, and studies suggest that roughly one in five to one in two patients report persistent dry-eye symptoms at six months or more after the procedure.11PubMed Central. Chronic dry eye symptoms after LASIK: parallels and lessons to be learned from other persistent post-operative pain disorders That is a wide range, and most of these cases are mild. But a subset develop chronic neuropathic pain similar to the mechanism described earlier with chronic dry eye, where the severed nerves regenerate abnormally and keep sending pain signals despite a healed surface.
After cataract surgery, a different and more dangerous form of eye pain can occur: endophthalmitis, an infection inside the eye itself. The most common symptom is pain with redness and sometimes a purulent discharge, and it is usually caused by bacteria like staphylococcus or streptococcus species that enter the eye during surgery.12Europe PMC. Endophthalmitis After Cataract Surgery: A Postoperative Complication Endophthalmitis is rare but vision-threatening and requires emergency treatment, sometimes including injection of antibiotics directly into the eye. Worsening pain in the days following any eye surgery should always prompt an urgent call to your surgeon.
Eye Pain in Children
When a child complains of eye pain, the diagnostic challenge is different from adults. A study of 80 preschool-aged children presenting with eye pain found that a full 91% were ultimately diagnosed with functional eye pain, meaning no structural or infectious cause could be identified.13Elsevier / PubMed Central. Eye pain in preschool children: diagnostic and prognostic significance On follow-up averaging about 21 months, 88% of those children still had no identifiable eye problem. The small minority with a real cause had conditions like dry eyes, allergic conjunctivitis, a corneal foreign body, or sinusitis.
This is reassuring, but it does not mean you should dismiss a child’s eye pain. The study underscores that a thorough initial evaluation is what allows you to confidently label the pain as functional. Red flags in children are similar to adults: visible redness, swelling, discharge, light sensitivity, or changes in vision all warrant a prompt exam. A child who repeatedly complains of eye pain but has a normal exam and no warning signs can generally be watched safely. Orbital cellulitis, mentioned earlier, deserves special vigilance in kids because it progresses quickly and is more common in pediatric patients who have had recent sinus infections.
Red Flags That Need Same-Day or Emergency Evaluation
Not every aching eye needs to send you to the ER, but certain patterns should. The following warrant urgent evaluation:
- Sudden severe pain: especially with nausea, vomiting, and halos around lights, which suggests acute angle-closure glaucoma.
- Vision loss: any eye pain accompanied by blurred or decreased vision that does not clear with blinking.
- Pain with eye movement: particularly if combined with vision changes, suggesting optic neuritis or orbital inflammation.
- Chemical exposure: irrigate first, then get to an emergency department regardless of how the eye feels afterward.
- Post-surgical worsening: increasing pain in the days after eye surgery, especially with discharge or declining vision.
- Contact lens pain: any significant pain, redness, or light sensitivity in a contact lens wearer that does not resolve within an hour of removing the lens.
- Proptosis or restricted movement: if the eye is bulging forward or you cannot move it normally, orbital cellulitis or another space-occupying process needs to be ruled out.
Pain that is mild, comes and goes, and is not accompanied by vision changes or redness is far less likely to represent something dangerous. But even low-grade chronic eye pain is worth mentioning at your next eye exam, especially if standard dry-eye treatments have not helped, since it may point to an underlying inflammatory or neuropathic process that requires a different approach.
Medications That Can Cause Eye Pain
A less commonly discussed angle is that the pill you are taking for an unrelated condition could be behind your eye discomfort. Several categories of medications have known ocular side effects. Topiramate, used for migraines and seizures, can cause acute angle-closure glaucoma by swelling the ciliary body and pushing the lens-iris complex forward. Some sulfonamide antibiotics carry the same risk through a similar mechanism. Bisphosphonates taken for osteoporosis have been linked to scleritis and uveitis. Even common antihistamines and anticholinergic drugs can worsen dry eye by reducing tear production, pushing someone who was borderline into symptomatic territory.
Medications that dilate the pupil, whether intentionally (like tropicamide drops used in eye exams) or as a side effect (certain antidepressants, decongestants), pose a particular risk in people with narrow drainage angles, as mentioned in the glaucoma section. If you have started a new medication and notice eye pain or visual changes that were not there before, it is worth checking whether ocular side effects are listed for that drug. Your pharmacist can usually pull this up quickly. Stopping or switching the medication, when possible, resolves the eye symptoms in most cases.