Scleritis is a deeper, more intense type of eye inflammation that affects the sclera—the firm “white” layer that helps the eye keep its shape. It often causes significant pain and redness and may be linked to inflammatory or autoimmune conditions elsewhere in the body.
Introduction: why it matters
A red eye is common, but a painful red eye that feels deep (not scratchy) deserves special attention because scleritis can threaten vision if it isn’t evaluated and treated appropriately. The goal of this article is to explain what scleritis is, what typically causes it, how clinicians diagnose it, and what treatment options may look like—without replacing an in-person eye exam.
What is Scleritis?
Scleritis is inflammation of the sclera, the tough, fibrous outer coat of the eye (the white part you see around the colored iris). It’s different from many surface problems because the inflammation is deeper and often produces a “boring,” aching pain rather than a mild gritty sensation.
Clinicians often describe scleritis by location and severity. For example, it can occur in the front portion of the eye (anterior scleritis) or farther back where it may be harder to see from the outside (posterior scleritis).
Causes and Risk Factors
Many cases of scleritis are “noninfectious,” meaning they are driven by inflammation rather than a direct germ infection. Scleritis can occur in people with systemic inflammatory or autoimmune diseases (bodywide immune conditions), and sometimes the eye symptoms are part of a larger health picture.
Less commonly, scleritis can be infectious (caused by microbes), and this distinction matters because the treatment approach is fundamentally different. One important risk in real life is that steroid drops (or other immunosuppressive treatment) can temporarily reduce redness and pain in infectious scleritis, which may delay correct diagnosis while the infection continues to progress.
Other risk-related context clinicians consider may include: recent eye surgery or trauma, contact lens–related infection risk behaviors, and underlying immune suppression (for example from systemic medications).
Common Signs and Symptoms
Scleritis commonly causes deep eye pain that can be constant and severe, sometimes disrupting sleep. The eye may look diffusely red, and the redness can appear violaceous (purplish) because the inflammation is deeper than typical “pink eye.”
Other possible symptoms include:
- Sensitivity to light (photophobia).
- Excess tearing/watering.
- Eye tenderness (soreness when the eyelid area is touched).
- Blurred vision or reduced sharpness in some cases.
A quick “symptom feel” comparison that many patients find helpful is this: dry eye often feels like sand or a lash on the surface, while scleritis tends to feel like the whole eye is sore from the inside.
Scleritis vs. episcleritis (a common look-alike)
How the Condition is Diagnosed
Diagnosis starts with an eye history and a careful eye exam, often including a slit-lamp examination to assess how deep the inflammation is. If posterior scleritis is suspected (inflammation toward the back of the eye), imaging such as ultrasound and/or CT may be used because the back of the sclera isn’t easily visible on routine external inspection.
When an infectious cause is possible, clinicians may take samples (for example, a smear of discharge) and, in uncommon situations, consider biopsy to identify the organism and guide treatment. If a systemic inflammatory condition is suspected, your eye clinician may coordinate with your primary care clinician or a specialist such as a rheumatologist for targeted medical evaluation.
Treatment Options Explained (non-prescriptive, informational)
Treatment depends on whether scleritis is noninfectious (immune-mediated) or infectious, as well as how severe it is and whether the back of the eye is involved. Because of that, the “right” treatment is not something to guess at home—especially not by using leftover drops.
For noninfectious scleritis, clinicians commonly use a stepwise approach that may include:
- Oral nonsteroidal anti-inflammatory drugs (NSAIDs) for milder cases when appropriate.
- Systemic corticosteroids if inflammation is more significant or if NSAIDs aren’t enough.
- Steroid-sparing immunomodulatory medications (sometimes including biologics) for severe, recurrent, necrotizing, or systemic-disease–associated cases, often with rheumatology collaboration.
For infectious scleritis, management typically shifts toward targeted antimicrobial therapy and may require a more aggressive combined approach (medical therapy plus surgical management in some situations). Reviews emphasize that delayed diagnosis and fungal causes are among factors linked to worse outcomes, which is one reason clinicians take the infectious possibility seriously.
Possible Complications if Left Untreated
Scleritis can be vision-threatening, and severe forms can cause tissue damage. Reported complications and consequences may include reduced visual sharpness, scleral thinning (“melting”), and—rarely—perforation in very severe disease (particularly necrotizing scleritis).
Posterior or necrotizing forms tend to be treated with extra urgency because they can be more damaging and harder to monitor from the outside. Even when vision is ultimately preserved, prolonged inflammation can lead to prolonged discomfort and a longer treatment course than many people expect.
Prevention and Risk Reduction (if applicable)
Not all cases of scleritis are preventable, especially when linked to autoimmune inflammation. Still, there are practical ways to reduce risk and catch problems earlier:
- Protect your eyes during high-risk work or sports with appropriate eye protection to reduce trauma-related risk.
- Reduce infection risk with good hand hygiene and proper contact lens cleaning habits.
- If you have an inflammatory/autoimmune condition, ongoing medical care may lower the chance of uncontrolled inflammation affecting the eyes, and clinicians often manage severe cases in coordination with rheumatology.
When to See an Eye Doctor
Seek urgent eye care for a red eye with significant pain—especially if the pain is deep, worsening, wakes you from sleep, or comes with light sensitivity or any vision change. Scleritis is generally not a “wait and see” problem, and reputable patient resources emphasize that it should be evaluated and treated rather than ignored.
If you have a known autoimmune or systemic inflammatory disease and develop a painful red eye, it’s reasonable to mention your medical history when booking care because it can influence the differential diagnosis.
Frequently Asked Questions (FAQ)
It can be urgent because it may threaten vision and can cause tissue damage if severe, so prompt evaluation is recommended for a painful red eye.
Scleritis is deeper inflammation and typically causes more intense, deep pain, while episcleritis involves a more superficial layer and often resolves on its own.
Some milder inflammatory eye conditions do, but scleritis is commonly described as needing medical evaluation and treatment rather than waiting it out.
Scleritis may occur in people with systemic rheumatic/autoimmune diseases such as rheumatoid arthritis, lupus, granulomatosis with polyangiitis, polyarteritis nodosa, or relapsing polychondritis.
Posterior scleritis may require imaging—commonly ultrasound and sometimes CT—to confirm because the inflammation is at the back of the eye.
Not always, but it may threaten vision and some people lose visual sharpness, particularly in severe disease—so early assessment matters.
If the cause is infectious scleritis, steroids can reduce symptoms temporarily while allowing infection to progress and delaying diagnosis, which can worsen outcomes.
Key Takeaways
Scleritis is inflammation of the sclera that often causes deep eye pain, redness, and light sensitivity, and it can be associated with systemic inflammatory disease or—less commonly—an infection. Diagnosis is clinical with an eye exam, and posterior cases may need imaging such as ultrasound or CT. Treatment depends on the cause and severity and may range from anti-inflammatory medications to systemic steroids and other immune-modifying therapies, while infectious cases require antimicrobial-focused care.
Medically reviewed / Educational disclaimer
This article is for general education and is not a substitute for diagnosis or treatment by a licensed eye care professional. If you have a painful red eye, light sensitivity, or any vision change, seek prompt in-person evaluation.
Authoritative sources (for further reading): Cleveland Clinic overview of scleritis (https://my.clevelandclinic.org/health/diseases/24975-scleritis), MSD Manual Consumer Version (https://www.msdmanuals.com/home/eye-disorders/conjunctival-and-scleral-disorders/scleritis), and peer-reviewed reviews on noninfectious and infectious scleritis management (https://pmc.ncbi.nlm.nih.gov/articles/PMC8785299/)
