Bloodshot Eye on One Side
A bloodshot eye on one side can be alarming, but it’s often a common issue. The most frequent cause is a small broken blood vessel on the white of the eye, called a subconjunctival hemorrhage, which usually looks worse than it feels and often goes away on its own. Other reasons for a red or bloodshot eye can include irritation, injury, allergies, dry eyes, or infections like pink eye.
Many people notice this sudden redness in just one eye, while the other eye looks normal. Most cases are not serious, but it’s important to recognize when redness could point to something that needs medical attention. Knowing what causes a bloodshot eye on one side helps people decide when to watch and wait, and when to see a doctor.
What Is a Bloodshot Eye on One Side?
A bloodshot eye on one side happens when only one eye develops noticeable redness or blood spots. This may look alarming, but the cause and possible concerns can differ based on how the eye looks and feels.
Understanding Unilateral Bloodshot Eyes
A bloodshot eye that affects just one eye is called unilateral. This means that only the right or left eye develops redness, while the other appears normal. Local irritation, injury, or a burst blood vessel in that eye can cause a bloodshot eye on one side.
For example, sneezing, coughing, or rubbing the eye too hard may result in this condition. Infections, allergies, or inflammation limited to one eye can also cause redness. Sometimes, a foreign object or chemical exposure irritates one eye but not the other.
Appearance and Physical Changes
A bloodshot eye on one side often stands out because the eye looks red or has streaks of blood on the white part, called the sclera. The redness can be mild, covering only a small area, or very dramatic, with a large, bright red patch. Other changes might include swelling, watering, or a gritty feeling in the affected eye. Sometimes, only small blood vessels are involved, causing slight pinkness.
In other cases, a larger blood vessel may break, which creates a more intense red spot. The bloodshot area may spread slowly or stay the same size. Most of the time, there is no pain. However, if pain occurs with redness, or if vision is affected, this could signal something more serious.
How a Bloodshot Eye Differs From Redness in Both Eyes
When only one eye is bloodshot, the cause is usually specific to that eye. This is different from redness in both eyes, which is more likely caused by conditions that affect both eyes at once, such as allergies, viral infections, or dry eyes. Eye redness in both eyes often comes from environmental irritants like pollen or smoke. These causes usually do not result in isolated redness.
Instead, they trigger inflammation in both eyes together. On the other hand, trauma, a burst blood vessel, or a foreign object will usually lead to bloodshot eyes on only one side. Key signs that suggest a one-sided issue include:
- Red or pink color is limited to one sclera.
- No symptoms in the other eye.
- Localized discomfort or a gritty feeling in only one eye.
If redness appears in both eyes, it is important to think about general causes such as infection or allergy, instead of an injury or specific local event.
Symptoms Accompanying a Bloodshot Eye on One Side
Symptoms that may appear along with a bloodshot eye on one side can help identify the cause and decide if medical care is needed. Some symptoms are mild and temporary, while others can signal more serious problems.
Eye Pain and Discomfort
Eye pain can range from mild irritation to sharp or throbbing pain. Discomfort might feel like burning, stinging, or a gritty sensation, making it hard to keep the eye open. If the pain comes with redness, it can point to issues like infections, injuries, or inflammation inside the eye. Serious pain that does not improve, or pain linked to decreased vision, may mean conditions such as uveitis or acute glaucoma.
Pay attention if the area around the eye gets tender to the touch or if moving the eye causes more pain. Pain with a bloodshot eye often needs quick evaluation by an eye doctor, as fast treatment can prevent vision loss.
Blurry Vision and Vision Changes
Blurry vision or sudden changes in vision in one eye are cause for concern. A red, bloodshot eye with blurry vision may suggest infection, corneal problems, or swelling inside the eye. Other vision changes, such as seeing floaters, dark spots, or losing part of the visual field, can signal something more serious like retinal detachment or eye stroke. These changes are especially concerning if they happen quickly.
| Symptom | Possible Significance |
|---|---|
| Blurry or hazy vision | Infection, swelling, or corneal injury |
| Sudden vision loss | Emergency (retinal or nerve problems) |
| Seeing floaters or flashes | Possible retinal issue |
Any new or sudden vision changes with a bloodshot eye need prompt medical attention.
Eye Discharge and Excessive Tearing
Eye discharge can appear as thin, watery fluid or as thick, yellow, or green pus. Excessive tearing may also happen, causing the eye to water much more than usual. Clear, watery discharge often points to allergy or a viral infection.
Thick, colored discharge is more common in bacterial infections and may crust over lashes. Both types can lead to irritation and make it hard to keep the eye open. A table can help summarize types of discharge:
| Discharge Type | Common Cause |
|---|---|
| Watery | Allergy, viral illness |
| Thick/yellow | Bacterial infection |
| Stringy/white | Allergy or dry eye |
If discharge makes vision cloudy or the eye sticks shut, it’s best to see a doctor for treatment.
Light Sensitivity and Halos Around Lights
Sensitivity to light makes it uncomfortable to be in bright rooms or sunlight. People may squint, blink, or shield their eye to feel better. Halos around lights can appear as glowing or colored rings, especially at night or in low light. These halos often mean the cornea is swollen or there is increased pressure inside the eye, which can signal emergencies like glaucoma.
Light sensitivity and halos are not usually seen with mild issues like dry eye. Their presence with redness may warn of more serious problems that need urgent care. If sensitivity or halos are new, persistent, or severe, an eye care professional should check them.
When to See an Ophthalmologist
Many things can cause a bloodshot eye on one side, such as allergies, infections, or minor injuries. Most cases are not serious, but sometimes they may signal a bigger problem. See an ophthalmologist if any of the following occur:
- Severe pain in the eye
- Sudden change or loss of vision
- Sensitivity to light
- Redness that does not improve after a few days
- Yellow or green discharge
- Swelling around the eye
- Fever with a red eye
If you recently injured your eye, get an eye exam soon, even if the pain does not seem severe. Eye trauma can cause hidden damage. Sometimes infections like pink eye start in one eye and can spread. If symptoms worsen over time, visit an eye specialist. Certain eye conditions, if not treated, can lead to permanent vision loss. Timely care from an ophthalmologist can protect eye health and prevent further problems.
If you have had recent eye surgeries, such as cataract or laser procedures, bloodshot eyes may indicate a complication. In this situation, book an eye exam with your ophthalmologist as soon as possible. When in doubt, it is safest to get a professional opinion. An eye specialist can rule out serious problems and suggest the right treatment.
Home Remedies
You can often help a bloodshot eye on one side with simple home remedies. First, try a cold compress to reduce redness and soothe discomfort. Place a clean, damp washcloth over your closed eye for several minutes. Over-the-counter eye drops can provide relief, especially if dryness or minor irritation causes the redness.
Choose lubricating or artificial tear drops. Avoid using drops meant to remove redness for long periods, as they can sometimes make things worse. Practice good hygiene. Wash your hands before touching your eyes and avoid rubbing them. If you wear contact lenses, clean them properly and remove them if your eye feels irritated.
Some people use natural remedies like rose water or cooled fennel seed water. Use these to gently rinse your eye, but always use clean, sterile water and never apply anything unsafe for the eyes. Getting enough rest and taking breaks from screens can help your eyes recover. Not getting enough sleep often makes bloodshot eyes worse. The table below shows some common home remedies and their uses:
| Home Remedy | Purpose |
|---|---|
| Cold compress | Reduces redness and swelling |
| Lubricating drops | Soothes dryness and irritation |
| Rest | Helps eye recover |
| Rose water rinse | Mild anti-inflammatory effect |
| Fennel seed water | Traditional eye cleansing |
| Good hygiene | Prevents further irritation |
