An injected sclera refers to redness in the white part of the eye, the sclera. This common occurrence happens when small blood vessels in the conjunctiva, a clear membrane covering the sclera, become swollen and more visible. This gives the eye a reddish or “bloodshot” appearance, indicating the vessels have dilated, allowing more blood flow to the eye’s surface.
Common Causes of Red Eyes
Many common factors can lead to temporary eye redness. Environmental irritants frequently cause this, as particles like dust, smoke, or pollen can irritate the eye’s surface. Exposure to chemicals, such as chlorine from swimming pools, also prompts blood vessels to dilate. These external factors trigger a localized inflammatory response, making vessels more noticeable.
Allergies are another frequent cause, where the body reacts to substances like pollen, pet dander, or mold spores. This allergic reaction releases histamines, causing conjunctival blood vessels to expand, resulting in redness and often itching. Insufficient sleep can also contribute to eye redness because the eyes do not receive adequate rest and lubrication, leading to dryness and irritation. Prolonged screen time, known as digital eye strain, reduces blinking frequency, causing the eyes to dry out and become irritated.
Underlying Medical Conditions and Injuries
Beyond everyday irritants, various medical conditions and injuries can cause an injected sclera. Conjunctivitis, commonly known as pink eye, involves inflammation of the conjunctiva and can be caused by bacterial, viral, or allergic agents. Bacterial conjunctivitis often produces a thick, colored discharge, while viral forms are typically associated with watery discharge and may accompany a cold.
Blepharitis, an inflammation of the eyelids, can also lead to chronic eye redness, often accompanied by crusting along the lash line. Uveitis, an inflammation of the middle layer of the eye (uvea), is a more serious condition that causes significant redness, pain, and light sensitivity. Improper use or prolonged wear of contact lenses can restrict oxygen flow to the cornea and conjunctiva, leading to irritation, infection, and noticeable redness. A subconjunctival hemorrhage occurs when a small blood vessel breaks underneath the conjunctiva, causing a bright red patch on the white of the eye; it is usually harmless and resolves on its own. Acute angle-closure glaucoma, a sudden increase in eye pressure, presents with severe redness, intense pain, blurred vision, and can be a medical emergency requiring immediate attention.
Associated Symptoms and When to See a Doctor
Recognizing accompanying symptoms is important for determining when medical attention is necessary. If eye redness is accompanied by significant eye pain, especially if it is severe or throbbing, a doctor should be consulted promptly. Changes in vision, such as new blurriness, double vision, or a sudden decrease in visual acuity, also warrant immediate medical evaluation.
Extreme sensitivity to light, known as photophobia, is another concerning symptom. The presence of a thick yellow or green discharge from the eye often indicates a bacterial infection. Any redness that develops after a direct injury to the eye should also be assessed by a healthcare professional to rule out more serious damage.
Distinguishing from Scleral Tattoos
It is important to differentiate an injected sclera from a scleral tattoo. An injected sclera results from dilated blood vessels and typically resolves as the underlying cause is addressed. In contrast, a scleral tattoo is a permanent cosmetic procedure involving the injection of ink directly into the white part of the eye to change its color.
Scleral tattooing carries significant health risks. Potential complications include chronic inflammation, infection, and permanent vision loss. Understanding this distinction is important, as one is a temporary bodily response, while the other is an irreversible body modification with serious potential consequences.