Pain in your right eye can mean anything from a minor scratch on the surface to a condition that needs same-day treatment. The location alone, right versus left, rarely points to a specific diagnosis. What matters more is the type of pain, how suddenly it started, and whether it came with other symptoms like vision changes, nausea, or sensitivity to light. Here’s what could be going on and how to tell the difference.
Surface Problems: Scratches and Infections
The most common reasons for one-eye pain are also the least dangerous. A corneal abrasion, essentially a scratch on the clear front layer of your eye, causes sharp, stinging pain that gets worse when you blink. You might have rubbed your eye, gotten something in it, or slept in contact lenses too long. Small scratches heal within 24 to 48 hours on their own, and even larger ones typically resolve within three to five days. Contact lens wearers face a higher risk of infection from a scratch, so they’re usually given antibiotic drops as a precaution.
Bacterial conjunctivitis (pink eye) often affects just one eye and produces a red, sore feeling along with sticky discharge. It’s uncomfortable but rarely serious in adults. A stye, which is a blocked oil gland on the eyelid, can also make one eye hurt with a tender, swollen bump near the lash line.
Deeper Causes: Inflammation Inside the Eye
When pain feels like it’s coming from behind the surface rather than on it, the issue may involve structures deeper inside the eye. Uveitis is inflammation of the middle layer of the eye wall, and it causes a deep ache, redness, light sensitivity, and sometimes blurry vision. It can develop in one or both eyes and is sometimes linked to autoimmune conditions, infections, or prior eye surgery. Diagnosis requires a slit lamp exam, where your eye doctor uses a microscope with a bright light to look at the internal structures of your eye.
Optic neuritis, inflammation of the nerve that connects the eye to the brain, produces a distinctive symptom: a dull ache behind the eye that gets noticeably worse when you move it. Some people also see flashing or flickering lights. It most often affects adults between ages 20 and 40 and can be an early sign of a neurological condition, so it’s worth getting evaluated promptly even if the pain is mild.
Sinus Pressure Behind the Eye
Your sinuses sit remarkably close to your eye sockets. The ethmoid sinuses are between your eyes, and the sphenoid sinus sits directly behind them. When these spaces get congested or infected, the pressure and inflammation can produce pain that feels like it’s coming from the eye itself, particularly behind it. This kind of pain usually comes with other sinus symptoms: a stuffy nose, facial pressure, or a headache that worsens when you bend forward. The pain tends to be constant and dull rather than sharp, and it typically improves as the sinus issue clears up.
Cluster Headaches and Migraines
If the pain around your right eye is severe, comes on fast, and lasts anywhere from 15 minutes to three hours, cluster headaches are a strong possibility. They’re one of the most painful conditions known, often described as a white-hot needle being pushed into the eye. Cluster headaches almost always strike the same side each time, so if your right eye is the target, it will likely be the target again. The eye on the affected side often tears up, the eyelid may droop, and the nostril on that side gets stuffy or runny.
These headaches tend to come in cycles. You might get several attacks a day for weeks or months, then have a pain-free stretch. They’re linked to activity in the hypothalamus, the part of the brain that regulates your internal clock, which helps explain why attacks often hit at the same time each day, frequently waking people from sleep.
Migraines can also produce intense pain around one eye, though they tend to last longer (four to 72 hours) and come with light sensitivity, sound sensitivity, or an aura. If you’re experiencing recurring one-sided eye pain with any of these features, tracking the timing, duration, and associated symptoms will help your doctor identify the pattern.
Acute Angle-Closure Glaucoma
This is the one to know about because it’s a true emergency. Acute angle-closure glaucoma happens when the drainage system inside the eye gets suddenly blocked, causing pressure to spike to dangerous levels. It causes severe pain in one eye, blurred vision, rainbow-colored halos around lights, nausea, and vomiting. The eye looks red, the cornea appears hazy or cloudy, and the pupil may be fixed and dilated.
Without treatment, the pressure damages the optic nerve and can cause permanent vision loss within hours. If you’re experiencing sudden, intense eye pain with vision changes and nausea, this is the reason not to wait it out.
When Eye Pain Needs Emergency Care
Not every instance of eye pain requires a trip to the emergency room, but certain combinations of symptoms do. Get emergency care if your eye pain is:
- Severe and paired with a headache, fever, or light sensitivity
- Accompanied by sudden vision changes
- Causing nausea or vomiting
- The result of a chemical splash or foreign object you can’t flush out
- Paired with halos around lights
- Accompanied by swelling in or around the eye
- Making it hard to move the eye or keep it open
- Producing blood or pus
Mild, dull aching that comes and goes, especially if you’ve been staring at screens or sleeping poorly, is far less concerning. Dry eyes and eye strain are among the most frequent causes of everyday eye discomfort and usually respond to breaks, lubricating drops, and better sleep.
What to Expect at Your Appointment
When you see an eye doctor for one-sided pain, the evaluation typically starts with a visual acuity test (reading a chart) and a slit lamp exam, which lets the doctor see the surface and interior of your eye under magnification. They’ll also measure your intraocular pressure using a tonometry test, a painless procedure where a small instrument briefly touches or blows a puff of air at the front of your eye. If your doctor suspects inflammation, nerve involvement, or something behind the eye, they may order blood work or an MRI of the brain and orbits.
The most useful thing you can bring to your appointment is a clear description: when the pain started, whether it’s sharp or dull, whether it’s constant or comes in waves, what makes it better or worse, and any other symptoms that showed up around the same time. These details narrow down the possibilities faster than any single test.