Pain at the side of your eye usually comes from something minor, like eye strain, a stye, or dry eyes. But depending on exactly where and how it hurts, it can also signal sinus pressure, a headache disorder, or a condition that needs prompt attention. The location, intensity, and timing of the pain all help narrow down the cause.
Eye Strain and Surface Irritation
The most common reason for pain around the side of the eye is straightforward: your eyes are tired or irritated. Hours of screen time, reading in dim light, or an outdated glasses prescription can create an aching sensation around the eye, especially at the outer edges where the muscles work hardest to focus. This type of pain tends to build gradually through the day and improve with rest.
Dry eyes can also produce a stinging or burning feeling that concentrates at the corners or sides. Wind, air conditioning, and long stretches without blinking (common during screen use) all make this worse. Contact lenses that don’t fit properly or that have been worn too long are another frequent culprit. Dirty or ill-fitting lenses create friction against the surface of the eye, and the resulting irritation can feel localized to one side.
Styes and Eyelid Infections
A tender bump near the outer edge of your eyelid is likely a stye, which is a blocked oil gland that has become infected. Styes cause localized, sometimes throbbing pain right at the side of the eye. You can usually see or feel a small swollen area, and the eyelid may look red or puffy.
A more diffuse eyelid infection, called preseptal cellulitis, causes broader swelling, warmth, redness, and tenderness across the lid. The key feature that separates a surface eyelid infection from a deeper problem is what happens when you open the eye: if the white of the eye looks normal, you can move your eye freely, and your vision is unchanged, the infection is confined to the lid and surrounding skin. Pain with eye movement, bulging, or blurry vision suggest the infection has spread deeper into the eye socket, which requires urgent care.
Sinus Pressure and Referred Pain
Your sinuses sit directly behind and beside your eyes. When they become inflamed or infected, the pressure can radiate into the eye area. The ethmoid sinuses, located between the eyes, and the maxillary sinuses, just below the eyes, are the most common sources of this referred pain. You’ll typically also have nasal congestion, a feeling of fullness in your face, or a headache that worsens when you lean forward.
In rare cases, a sinus infection can spread into the eye socket itself. This causes more dramatic symptoms: significant swelling, pain that worsens when you try to look around, blurred vision, and sometimes a visibly bulging eye. That progression is uncommon, but it’s the reason persistent sinus pain combined with eye symptoms deserves medical evaluation.
Cluster Headaches and Migraines
If the pain at the side of your eye is intense, comes on suddenly, and happens in episodes, a headache disorder is a strong possibility. Cluster headaches are particularly recognizable because they produce extreme sharp or stabbing pain in, behind, or around one eye. A single attack typically lasts 30 to 45 minutes but can range from 15 minutes to 3 hours. During a cluster period, these headaches often strike multiple times per day, frequently at the same time of night.
Cluster headaches also come with distinctive companion symptoms on the same side as the pain: a watery or red eye, a drooping eyelid, nasal congestion, or a runny nostril. These features help distinguish a cluster headache from a migraine, which more often involves sensitivity to light and sound, nausea, and pain that may spread across one side of the head rather than staying tightly focused around the eye.
Acute Glaucoma
Acute angle-closure glaucoma happens when fluid pressure inside the eye spikes suddenly. This causes severe eye pain, often accompanied by a bad headache, nausea or vomiting, blurred vision, halos or colored rings around lights, and noticeable eye redness. The pain can feel like it’s concentrated on one side of the eye or deep behind it.
This is a medical emergency. Without rapid treatment, the elevated pressure can permanently damage the optic nerve and cause irreversible vision loss. If you have sudden, severe eye pain paired with any of these symptoms, go to an emergency room immediately.
Temporal Arteritis
For adults over 50, pain at the temple or the outer side of the eye raises the possibility of giant cell arteritis (also called temporal arteritis). This is inflammation of the blood vessels along the temples and scalp. The hallmark is persistent, often severe head pain in the temple area. It can also cause vision loss or double vision, jaw pain while chewing, scalp tenderness, and general fatigue or fever.
Most people who develop this condition are between 70 and 80 years old, and it rarely occurs in anyone under 50. Because untreated temporal arteritis can lead to sudden, permanent vision loss in one eye, it requires prompt diagnosis and treatment.
How to Tell What’s Serious
Most side-of-eye pain resolves on its own or with simple measures like resting your eyes, using lubricating drops, or applying a warm compress to a stye. The pattern of the pain is your best guide to whether something more is going on. Dull, achy pain that improves with rest is rarely urgent. Sharp or severe pain that comes on suddenly is more concerning.
Seek emergency care if your eye pain is severe or accompanied by a headache, fever, or increased light sensitivity. The same applies if your vision changes suddenly, you experience nausea or vomiting, you see halos around lights, or you notice swelling in or around the eye. Trouble moving your eye, inability to keep it open, or blood or pus coming from the eye also warrant immediate attention. These symptoms can indicate conditions like acute glaucoma, deep orbital infection, or vascular inflammation where early treatment makes a significant difference in the outcome.