Eye pain: causes and what to do

Eye pain is a symptom that can originate in the cornea, conjunctiva, eyelids, sclera, anterior chamber, orbit, optic nerve, or periorbital structures. The International Classification of Diseases, 10th revision, uses the code H57.1 for eye pain. However, this code only designates the complaint, not a definitive diagnosis, so the physician's task with this type of pain is to find the source of the symptom and rule out vision-threatening conditions. [1]

From a clinical perspective, eye pain is conveniently divided into superficial and deep. Superficial pain is most often associated with the ocular surface and adnexa: dry eye, blepharitis, styes, corneal erosions, foreign bodies, conjunctivitis, and keratitis. Deep or boring pain suggests scleritis, uveitis, acute angle closure, orbital inflammation, or optic nerve pathology. This distinction is especially useful during the initial consultation. [2]

This symptom cannot be assessed in isolation from vision. Pain without decreased vision or photophobia is more common with more superficial and benign causes, although there are exceptions. Pain combined with decreased vision, photophobia, limbal redness, nausea, halos, proptosis, or pain with eye movement requires a completely different level of vigilance. This is why modern algorithms for assessing a painful eye always begin with a visual acuity test and anterior segment examination. [3]

Referred and neurogenic pain is a separate issue. Sometimes a patient describes severe pain "inside the eye," while examination of the ocular surface and anterior segment reveals no significant changes. In such cases, optic neuritis, migraine, trigeminal pain syndromes, sinus pathology, or neuropathic ocular pain should be considered. This is considered a diagnosis of exclusion and can be accompanied by severe sensations with minimal objective findings. [4]

From a practical standpoint, eye pain is a symptom with a very broad range of significance. At one extreme are dry eye and uncomplicated hordeolum, while at the other are microbial keratitis, orbital cellulitis, chemical burns, and acute attacks of angle closure. Therefore, modern information on this topic must answer not only the question "why does it hurt" but also the more important question: "when is it dangerous and what should be done immediately?" [5]

Table 1. How eye pain is usually classified

Type of pain	Where is the source usually located?	The most common reasons
Superficial, burning, cutting	Cornea, conjunctiva, eyelids, tear film	Dry eye syndrome, blepharitis, stye, corneal erosion, foreign body, conjunctivitis
Deep, drilling	Sclera, iris, ciliary body, structures with increased intraocular pressure	Scleritis, anterior uveitis, acute attack of anterior chamber angle closure
Pain when moving eyes	Optic nerve, orbit, extraocular muscles	Optic neuritis, orbital cellulitis
Pain after injury or chemical contact	Ocular surface and deeper structures	Erosion, foreign body, chemical burn, penetrating trauma
Pain with minimal findings	Nerve pathways or referred pain	Neuropathic eye pain, migraine, sinus pathology

Sources for the table. [6]

The most common superficial causes

One of the most common causes of complaints of pain, burning, and a scratchy sensation is dry eye syndrome. Current ophthalmological guidelines consider it a multifactorial disease of the ocular surface with a disruption of tear film homeostasis, where tear film instability, hyperosmolarity, inflammation, and neurosensory disturbances play a significant role. In practice, patients most often complain of burning, stinging, a gritty sensation, eye fatigue in the evening, and an increase in symptoms with screen time, wind, dry air, and contact lens wear. [7]

Dry eye isn't always benign. Updated clinical guidelines for 2024 and 2025 emphasize stepwise treatment: from eliminating triggers, artificial tears, and eyelid hygiene to anti-inflammatory agents and more specialized treatments if symptoms and signs persist. This is important because long-term untreated dry eye syndrome can lead to chronic ocular surface pain, epithelial damage, and a significant deterioration in quality of life. [8]

Blepharitis and styes also often cause eye pain, although the anatomical source is located in the eyelids. A sty is an acute, painful inflammation of the sebaceous glands of the eyelid and typically presents with localized redness, soreness, and swelling along the eyelid margin. Blepharitis often causes chronic discomfort, burning, crusting of the eyelashes, tear film instability, and secondary irritation of the ocular surface. [9]

Corneal erosions and superficial foreign bodies are classic causes of sudden, sharp pain, photophobia, lacrimation, and blepharospasm. The cornea is highly innervated, so even a small epithelial defect can be very painful. Most uncomplicated superficial erosions heal within 3-5 days, but contact lens defects, decreased vision, central location, and the presence of an infiltrate require closer monitoring. [10]

Conjunctivitis can be accompanied by discomfort and even pain, but with a simple allergic form, severe pain and decreased vision are uncommon. If a patient with "red eye" complains of severe pain, noticeable photophobia, or deteriorating vision, it's important to consider keratitis, uveitis, scleritis, or glaucoma rather than a simple allergic reaction. This is especially important in primary care, where misattributing severe pain to "conjunctivitis" can delay a proper diagnosis. [11]

Table 2. Common superficial causes and their clinical clues

Cause	How it usually manifests itself	What is especially important
Dry eye syndrome	Burning, stinging, sand, eye fatigue	Increases in intensity in the evening, with screens, wind, and dry air
Blepharitis	Burning, irritation, crusting on eyelashes	Often associated with an unstable tear film
Barley	Localized painful swelling of the eyelid	The source of pain is in the eyelid, not in the eyeball
Corneal erosion	Sudden sharp pain, photophobia, tears	Usually heals quickly, but requires examination.
Foreign body	Feeling of speck, burning, tearing	It is necessary to exclude a hidden foreign body under the eyelid.
Conjunctivitis	Redness, discharge, moderate discomfort	Severe pain forces one to seek another diagnosis

Sources for the table. [12]

Deep pain and conditions that are often dangerous

Keratitis is an inflammation of the cornea, whether infectious or non-infectious. Clinically, infectious keratitis is particularly dangerous because it can quickly progress to a corneal ulcer, scarring, and vision loss. Contact lens wearers are at higher risk, and patients with pain, photophobia, redness, blurred vision, or corneal defects should be considered an emergency until proven otherwise. [13]

Scleritis causes deep, often very severe, sometimes radiating pain and is often associated with a systemic disease. It is important to distinguish it from episcleritis, which is typically milder, characterized by more superficial inflammation, and is often self-limited. In practice, this is one of the most important distinctions: a "red, painful eye" associated with scleritis requires a much more thorough evaluation and treatment than one associated with episcleritis. [14]

Anterior uveitis, or iridocyclitis, is another key cause of red, painful eye. It is characterized by pain, photophobia, limbal redness, blurred vision, and inflammatory cells in the anterior chamber fluid. It is important to remember that uveitis can be the first manifestation of an infectious, autoimmune, or systemic disease, and improper self-treatment can lead to synechiae, secondary glaucoma, and persistent vision loss. [15]

An acute attack of angle closure is one of the most dangerous causes of eye pain. It typically presents with sudden, severe, unilateral pain, redness, blurred vision, halos around lights, headache, nausea, and vomiting. This type of attack requires immediate ophthalmological care rather than home observation, as delay increases the risk of irreversible optic nerve damage. [16]

Pain with eye movements is a significant clue to another group of diagnoses. It is characteristic of optic neuritis, in which pain often precedes vision loss and is associated with impaired color vision, as well as orbital cellulitis, which also includes proptosis, limited eye movement, eyelid edema, fever, and sometimes double vision. Both conditions require urgent evaluation by a specialist, but the route differs: neuritis requires a neuro-ophthalmological and neurological assessment, while orbital cellulitis requires emergency infectious and ophthalmological care. [17]

Table 3. Deep pain and dangerous causes

Cause	Typical signs	Why is it dangerous?
Infectious keratitis	Pain, photophobia, redness, decreased vision, corneal infiltrate	Scarring, perforation, vision loss
Scleritis	Deep, severe pain, sometimes radiating, redness	Frequent association with systemic disease and risk of complications
Anterior uveitis	Pain, photophobia, limbal redness, blurring	Risk of adhesions, increased intraocular pressure, and vision loss
Acute attack of angle closure	Severe pain, halos, nausea, vomiting, blurred vision	Rapid damage to the optic nerve
Optic neuritis	Pain when moving the eyes, decreased vision, deterioration of color perception	May be a manifestation of demyelinating disease
Orbital cellulitis	Pain with eye movements, proptosis, ophthalmoplegia, eyelid edema, fever	Threat to vision and life

Sources for the table. [18]

When Eye Pain Is Dangerous: Red Flags

The first and most important red flag is decreased vision. Even if the pain seems tolerable, the combination of pain and decreased visual acuity immediately increases the likelihood of serious intraocular or corneal pathology. In algorithms for assessing a painful eye, a vision examination is considered a mandatory step because it helps distinguish some superficial conditions from more serious ones. [19]

The second warning sign is severe photophobia. This is typical for corneal and anterior segment lesions, especially corneal erosions, keratitis, and uveitis. If the patient reports not just discomfort but an inability to tolerate light, one should not rely on a diagnosis of "overstrain" or "allergy" without a full anterior segment examination and fluorescein staining of the cornea. [20]

The third important red flag is contact lens pain. Any new eye pain in a contact lens wearer should raise concerns about infectious keratitis and corneal ulcers, especially if accompanied by redness, photophobia, and blurred vision. This situation typically requires a low same-day referral threshold, as contact lens-induced microbial keratitis can quickly lead to irreversible corneal damage.

The fourth group of red flags involves the orbit and optic nerve. Pain with eye movement, proptosis, diplopia, limited eye movement, and fever are particularly characteristic of orbital cellulitis. Pain with eye movement combined with decreased vision and changes in color perception is more typical of optic neuritis. Both scenarios require urgent evaluation but should not be confused. [21]

The fifth group includes chemical burns and penetrating or high-velocity trauma. In the case of chemical exposure, immediate and copious rinsing of the eye is a priority, even before completing the diagnostic evaluation, as tissue damage continues after contact with the substance. Alkali burns are particularly dangerous due to their rapid and deep tissue penetration, and the degree of limbal ischemia is considered one of the most important prognostic indicators. [22]

Table 4. Red flags for eye pain

Sign	What should be excluded first?
Decreased vision	Keratitis, uveitis, glaucoma, neuritis, orbital pathology
Severe photophobia	Corneal erosion, keratitis, anterior uveitis
Contact lenses and pain	Microbial keratitis, corneal ulcer
Halos, nausea, vomiting, severe one-sided pain	Acute attack of anterior chamber angle closure
Pain when moving eyes	Optic neuritis, orbital cellulitis
Proptosis, limited movement, fever	Orbital cellulitis
Chemical burn	Urgent irrigation and ophthalmologic emergencies
High-velocity trauma	Penetrating trauma, intraocular foreign body

Sources for the table. [23]

Diagnostics: What's Really Important in the First Stage

Evaluation of a painful eye begins with simple but critical steps: checking visual acuity, examining the eyelids, conjunctiva, sclera, cornea, pupils, anterior chamber, and the nature of the redness. The American Academy of Family Physicians emphasizes that at this stage, the physician should recognize whether the pain is the first sign of an ophthalmic emergency. In an outpatient setting, this is often more valuable than immediate, complex imaging. [24]

Fluorescein staining and intraocular pressure measurement are often the next key steps. Staining helps visualize erosions, foreign bodies, ulcers, herpetic lesions, and other epithelial defects. Tonometry is especially important when pain is accompanied by nausea, halos, and blurred vision, i.e., when an acute attack of angle closure is suspected. [25]

The slit lamp remains a central diagnostic tool. In uveitis, it allows one to visualize cells and protein in the anterior chamber, precipitates on the corneal endothelium, and synechiae. In keratitis, it helps assess the infiltrate, the depth of the lesion, and the condition of the epithelium. In chemical burns, it allows one to assess limbal ischemia, and in scleritis and episcleritis, it helps to clarify the depth of inflammation and rule out other dangerous pathologies. [26]

If the clinical picture points to the orbit or optic nerve, a slit lamp alone is no longer sufficient. If orbital cellulitis is suspected, an examination of eye movements, identification of proptosis and ophthalmoplegia, and, if necessary, urgent imaging of the orbits and sinuses are important. Optic neuritis requires a neuro-ophthalmological evaluation and often magnetic resonance imaging, as this condition may be associated with a demyelinating disease of the central nervous system. [27]

Severe pain with minimal findings creates a separate diagnostic pitfall. If the eye appears almost calm, but the complaints are disproportionately severe, neuropathic ocular pain, migraine, cluster headache, sinus pathology, and other non-ophthalmologic causes should be considered. However, such a conclusion is only permissible after corneal pathology, uveitis, glaucoma, orbital inflammation, and optic neuritis have been excluded. Neuropathic ocular surface pain is considered a diagnosis of exclusion, not a default diagnosis. [28]

Table 5. How eye pain is usually diagnosed

Stage	What is being assessed?	Why is this necessary?
1	Visual acuity	Quickly identify dangerous conditions
2	The nature of the redness, the condition of the eyelids and cornea	Distinguish between superficial and deep causes
3	Fluorescein staining	Find erosion, ulcer, foreign body, epithelial defect
4	Measuring intraocular pressure	Exclude an acute attack of anterior chamber angle closure
5	Slit lamp	Identify uveitis, keratitis, and the depth of the lesion
6	Evaluation of eye movements and proptosis	Eliminate orbital process
7	Neuroimaging as indicated	Necessary if neuritis or orbital complication is suspected.

Sources for the table. [29]

Treatment: from simple causes to emergency conditions

Treatment for eye pain should always be causal, not just pain-relieving. For dry eye syndrome, current guidelines recommend stepwise therapy: control of environmental factors, reduction of eye strain, preservative-free artificial tears when indicated, eyelid hygiene, and then, if necessary, anti-inflammatory and more specialized treatments. The 2025 consensus specifically emphasizes that measures that replenish, preserve, and stimulate the tear film remain the basis of treatment. [30]

In cases of styes and some cases of blepharitis, warm compresses, eyelid hygiene, and monitoring of progression play a key role. However, if localized eyelid swelling is accompanied by eyeball pain, decreased vision, diffuse swelling of the orbital tissue, or limited eye movement, this is no longer a typical stye and requires urgent examination to rule out pre- and post-septal infections. [31]

In corneal erosions, the primary goals are pain relief, infection prevention, and epithelial healing. Simply patching the eye is no longer considered a good tactic for uncomplicated injuries. If the defect is associated with contact lenses, prompt topical antibiotics with activity against Pseudomonas aeruginosa and daily monitoring are necessary, as the risk of progression to bacterial keratitis is particularly high in this group. [32]

Keratitis, uveitis, and acute attacks of anterior chamber angle closure require specialized treatment. For anterior uveitis, topical glucocorticosteroids and cycloplegics under the supervision of an ophthalmologist are standard. In acute attacks of anterior chamber angle closure, intraocular pressure should be rapidly reduced with medication, and laser peripheral iridotomy remains the treatment of choice for further removal of the block. For infectious keratitis, the strategy is determined by the suspected pathogen and its severity, but the principle remains the same: delay is dangerous to vision. [33]

Orbital cellulitis and chemical burns belong to a different category of urgency. Orbital cellulitis requires not home therapy but urgent hospital treatment with systemic treatment and monitoring for complications. In the case of a chemical burn, immediate and copious irrigation until the ocular surface acidity returns to normal is the absolute priority. Only then can a full examination be performed and anti-inflammatory, antibacterial, and restorative therapy decided upon. Every minute can impact the prognosis. [34]

Table 6. Basic principles of treatment depending on the cause

Cause	Basic tactics
Dry eye syndrome	Artificial tears, environmental and stress correction, eyelid hygiene, and anti-inflammatory therapy as indicated
Blepharitis and barley	Eyelid hygiene, warm compresses, observation
Corneal erosion	Pain relief, epithelial protection, antibiotics as indicated
Contact lens epithelial defect	Urgent examination, local antipseudomonas agents, daily monitoring
Anterior uveitis	Topical glucocorticosteroids and cycloplegics under ophthalmologist supervision
Acute attack of anterior chamber angle closure	Urgent reduction of intraocular pressure, then laser peripheral iridotomy
Orbital cellulitis	Urgent specialized care, systemic therapy
Chemical burn	Immediate copious rinsing, then specialized treatment

Sources for the table. [35]

Prevention and prognosis

The prognosis for eye pain is highly variable. Dry eye, blepharitis, and most uncomplicated superficial erosions have a good prognosis, especially if the underlying factors are eliminated and treatment is initiated promptly. Minor superficial corneal erosions typically heal within a few days, and full recovery is expected in most patients. [36]

However, the good prognosis quickly deteriorates if the pain is accompanied by contact lenses, corneal infiltrates, visual impairment, deep pain, severe photophobia, pain with eye movement, or chemical contact. These signs are no longer associated with superficial irritation, but with the threat of corneal scarring, intraocular inflammation, optic nerve damage, or spread of infection to the orbit. Early triage for red flags has the greatest impact on outcome. [37]

Prevention depends on the cause. For the ocular surface, a rational screen-use regimen, air dryness control, proper eyelid care, and avoiding traumatic eye rubbing are particularly important. To prevent erosions and foreign bodies, the use of protective eyewear when working with metal, wood, construction materials, and chemicals is critical. The proportion of preventable injuries from occupational eye injuries remains high. [38]

Proper contact lens wear is crucial. Eye pain in a contact lens wearer is not a situation where it is appropriate to continue wearing the lens "until an appointment." Current data confirm that contact lenses are a major risk factor for microbial keratitis, including severe cases with the risk of permanent vision loss. Therefore, the basis for prevention is hand hygiene, adherence to the lens-wearing regimen, and immediate discontinuation of lens use if pain, redness, or photophobia occurs. [39]

For emergency situations, the main prognostic factor is time. In an acute attack of angle closure, the hours until intraocular pressure decreases are crucial; in orbital cellulitis, the speed of initiation of systemic treatment is crucial; in a chemical burn, the minutes before irrigation begins. Therefore, when experiencing eye pain, the best way to improve the prognosis is not to spend a long time trying to determine the cause on your own, but to quickly distinguish "irritation" from signs of a threat to vision and act without delay. [40]

Frequently Asked Questions

Does eye pain always indicate inflammation of the eye itself?
No. Pain can originate from the cornea, eyelids, orbit, optic nerve, or even be referred and neurogenic. Therefore, a normal-appearing eye does not always rule out a serious cause. [41]

Is it possible to differentiate dry eye from a dangerous condition based on a single symptom?
No. Dry eye most often causes burning, gritty sensations, and worsening in the evening, but similar complaints can accompany more serious illnesses. The main warning signs are decreased vision, severe photophobia, pronounced redness, pain with eye movement, and wearing contact lenses while experiencing pain. [42]

Why are contact lenses so dangerous when you're experiencing pain?
Because they significantly increase the risk of microbial keratitis and corneal ulcers. If you experience pain, redness, or photophobia, remove your lenses immediately and don't wear them again until you've seen a specialist. [43]

Do home pain relief drops help?
Self-administration of topical anesthetics at home is not considered a safe, standard approach. They can mask deterioration and interfere with healing, especially with corneal lesions. [44]

When does eye pain require not just a visit, but immediate help?
Immediately – in cases of chemical burns, trauma, sudden deterioration of vision, severe one-sided pain with nausea and halos, pain with eye movements with proptosis or double vision, as well as pain in contact lens wearers. [45]

Can allergic conjunctivitis cause severe pain?
Severe pain and decreased vision are uncommon in simple allergic conjunctivitis. If they are present, another diagnosis should be considered. [46]

Is an MRI always necessary for pain?
No. Most patients first require a proper ophthalmological examination. Imaging is usually required when orbital disease, optic neuritis, traumatic complications, or other underlying pathology are suspected. [47]

Key points from experts

Guillermo Amezcua, MD, professor of clinical ophthalmology and medical director of the Ocular Surface Disease Program at the Bascom Palmer Eye Institute, is one of the authors of the American Academy of Ophthalmology's dry eye guidelines. His practical thesis for this topic is that ocular surface pain cannot be dismissed as a mere "dryness" complaint: modern management requires assessment of tear film stability, inflammation, eyelid function, and a stepwise approach to therapy. [48]

Anat Galor, MD, MPH, is a cornea, uveitis, and ocular surface pain specialist at the Bascom Palmer Eye Institute. Her clinical perspective is particularly important for patients with severe pain and minimal objective findings: such pain may be neuropathic, meaning the physician should not conclude that the eye is normal, so there is no problem. [49]

Amy Lin, MD, a corneal and anterior segment specialist at the John Moran Eye Center at the University of Utah, is a co-author of updated ophthalmology guidelines for blepharitis. Her practice point fits well with the topic of eye pain: not all pain originates in the eyeball, and a significant portion of complaints originate in the eyelids, meibomian gland dysfunction, and secondary ocular surface instability. [50]

Andrew G. Lee, MD, is director of the Blanton Eye Institute at Houston Methodist Hospital and professor of ophthalmology, neurology, and neurosurgery at Weill Cornell Medical College. His area of expertise is particularly important when eye pain is not conjunctival or corneal, but rather optic nerve and neuro-ophthalmological. The key takeaway here is that pain with eye movements and visual disturbances require consideration of optic neuritis and other neuro-ophthalmological causes before simple eye strain. [51]

Conclusion

Eye pain is a symptom with a very wide range of causes: from dry eye, blepharitis, and corneal erosions to uveitis, scleritis, microbial keratitis, orbital cellulitis, and acute attack of angle closure. The most useful modern approach is to first classify the pain as superficial, deep, and orbital or optic nerve related, then immediately check for red flags, vision, and corneal condition. The most dangerous mistakes occur when severe pain is attributed to "conjunctivitis" or "eye fatigue" without assessing vision, photophobia, contact lenses, intraocular pressure, and pain with eye movements. [52]

In the new evidence-based model for managing painful eyes, time remains the deciding factor. Superficial uncomplicated causes generally have a good prognosis, while acute attacks of glaucoma, infectious keratitis, orbital cellulitis, and chemical burns require immediate action. [53]