Eye pain has dozens of possible causes, ranging from a minor scratch on the surface of your eye to serious conditions that need same-day treatment. The type of pain you feel, where exactly you feel it, and whether your vision is affected all point toward different causes. Most eye pain falls into two broad categories: pain that starts on the surface of the eye and pain that originates deeper, behind or around the eyeball.
Surface Pain: Scratches, Dryness, and Infections
The most common source of eye pain is something irritating the outermost layer of the eye, the cornea. This surface is packed with nerve endings, which is why even a tiny scratch can produce sharp, disproportionate pain.
A corneal abrasion, or scratch on the eye’s surface, causes a sudden stinging or stabbing sensation along with the persistent feeling that something is stuck in your eye. Your eye will water heavily, turn red, and become sensitive to light. Contact lenses, fingernails, dust, and sand are the usual culprits. Minor scratches heal within 24 to 48 hours because corneal cells reproduce rapidly, though larger abrasions take longer.
Dry eye is a subtler but extremely common cause of chronic eye discomfort. When your tear film breaks down or evaporates too quickly, the nerve endings in your cornea become exposed and irritated. Over time, this repeated irritation can actually lower the threshold at which those nerves fire, meaning your eyes start to hurt even under normal conditions. People with chronic dry eye often describe burning, aching, or a gritty sensation that worsens throughout the day, especially after prolonged screen use or in dry environments.
Conjunctivitis, commonly called pink eye, produces redness, discharge, and varying degrees of pain depending on the cause. Viral and allergic forms tend to cause itching and watering more than true pain. Bacterial infections produce thicker discharge and more irritation. A severe form called hyperacute bacterial conjunctivitis can cause intense pain, heavy pus-like discharge, significant swelling, and even decreased vision.
Deep Eye Pain and Pressure
Pain that feels like it’s coming from behind the eye or deep within the socket points to a different set of causes. This type of ache is often described as a dull pressure, though it can also be sharp and throbbing.
Uveitis is inflammation inside the eye itself. It causes a deep, aching pain along with redness concentrated in a ring around the colored part of your eye, light sensitivity, blurred vision, and sometimes floaters. One distinctive feature: if you have uveitis in one eye, shining a light into your healthy eye will cause pain in the affected one. Uveitis needs prompt treatment to prevent vision loss.
Optic neuritis, inflammation of the nerve connecting the eye to the brain, produces a characteristic pain that worsens when you move your eyes. Vision typically dims or blurs in one eye, and colors may look washed out. This condition is sometimes an early sign of multiple sclerosis, though it can also occur on its own. The combination of pain on eye movement plus vision changes is considered a hallmark of the condition.
Sinus Pressure and Headaches
Not all eye pain starts in the eye. The sinuses sit directly behind and below your eye sockets, and when they become inflamed, the pressure can feel like it’s coming from behind the eyeball. Typical sinus-related eye pain feels like a dull facial pressure, but when the inflammation pushes into the orbital area, the pain becomes sharper and deeper. Patients often describe a retro-orbital ache, meaning it feels lodged behind the eye. In chronic sinusitis, expanding tissue can stretch the well-innervated lining of the bone around the orbit, producing persistent discomfort that’s easy to mistake for an eye problem.
Cluster headaches cause some of the most intense eye pain you can experience. They produce extreme stabbing pain in, behind, or around one eye, and they’re widely considered the most painful type of headache. A single attack typically lasts 30 to 45 minutes, though episodes can range from 15 minutes to 3 hours. These headaches come in clusters, striking repeatedly over weeks or months, often at the same time of day. The affected eye usually tears up, turns red, and the eyelid may droop or swell during an attack.
Migraines can also produce significant pain around one eye, often accompanied by nausea, light sensitivity, and visual disturbances like flickering lights or blind spots.
Acute Angle-Closure Glaucoma
This is one of the true emergencies that causes eye pain. It happens when fluid drainage inside the eye suddenly becomes blocked, causing pressure to build rapidly. The symptoms come on fast: severe pain in one eye, redness, blurred vision, seeing rainbow-colored halos around lights, headache, and nausea or vomiting. The cornea may appear hazy or steamy.
Acute angle-closure glaucoma requires immediate treatment. Without it, the sustained high pressure inside the eye can permanently damage the optic nerve within hours. If you experience sudden severe eye pain with vision changes and nausea, this is the scenario that makes it urgent.
Eye Strain and Digital Fatigue
For many people searching for what causes eye pain, the answer is less dramatic but no less real. Prolonged close-focus work, especially on screens, forces the muscles inside and around your eyes to sustain contraction for hours. The result is a tired, aching sensation around the eyes that can spread into headache territory. Poor lighting, uncorrected vision problems, and working at the wrong distance all make it worse. This type of pain typically resolves with rest and doesn’t involve redness, discharge, or vision loss.
Trauma and Chemical Exposure
Any direct blow to the eye can cause pain from bruising, a scratched cornea, or more serious internal damage. A foreign object embedded in the eye produces constant sharp pain, tearing, and the inability to open your eye comfortably. If you suspect something has punctured the eye, avoid rubbing or pressing on it.
Chemical splashes are particularly time-sensitive. Alkaline substances like cleaning products and cement dust penetrate eye tissue quickly and can cause deep damage. Immediate, prolonged flushing with water is the single most important first step, even before getting to an emergency room.
Warning Signs That Need Urgent Attention
Certain combinations of symptoms suggest causes that can threaten your vision if left untreated:
- Sudden severe pain with nausea and halos around lights suggests acute angle-closure glaucoma.
- Pain with a red eye and light sensitivity after recent eye surgery, especially 7 to 10 days after cataract surgery, could indicate a serious internal infection.
- Pain on eye movement with dimming vision points to optic neuritis.
- Flashing lights like bolts of lightning, a sudden increase in floaters, or a dark shadow across your vision may signal a retinal detachment, which is painless but often accompanies other painful conditions and needs evaluation within 24 hours.
- Deep aching pain with a ring of redness around the iris suggests uveitis.
Mild eye pain from strain, minor dryness, or a small scratch often resolves on its own within a day or two. Pain that persists beyond 48 hours, worsens steadily, or comes with any vision change warrants professional evaluation, because the conditions that cause lasting eye pain generally respond much better to early treatment.