Most people assume color blindness affects both eyes equally—but in rare cases, it can occur in just one. If you’ve noticed that one eye seems to see colors differently than the other, this could indicate an underlying issue that needs attention. While inherited color vision deficiency typically shows up in both eyes and is often detected in childhood eye exams, changes in color vision affecting only one eye are usually acquired later in life.
This is why routine eye exams for both children and adults are so important. Eye exams help catch subtle changes in vision early—including rare conditions like one-sided color blindness—and ensure that your eyes stay healthy at every age.
What Is Color Blindness?
Color blindness, or color vision deficiency, is a condition that affects how someone perceives colours. The most common form is red-green color blindness, where reds and greens can appear similar or muted. Less common types affect blue-yellow discrimination or cause nearly complete color blindness (monochromacy).
Most cases of color blindness are inherited and affect both eyes equally. This happens due to missing or malfunctioning cones—the color-sensitive cells in the retina.
Can Color Blindness Really Affect Just One Eye?
Yes—but it’s uncommon.
When someone experiences color blindness in only one eye, it’s usually not genetic. Instead, it’s considered acquired color vision deficiency, meaning it develops due to another condition that affects the eye or visual processing system.
In these cases, one eye may process color normally, while the other eye struggles to differentiate between hues, perceives desaturated color, or shows noticeable changes in contrast or brightness.
Possible Causes of Color Blindness in One Eye
Color vision issues in one eye typically point to an underlying problem that needs medical attention. Some possible causes include:
Optic Nerve Damage
The optic nerve transmits visual information from the eye to the brain. Damage to this nerve—due to inflammation, trauma, or disease—can impair how the brain interprets color signals.
Optic neuritis, for example, is a condition where inflammation of the optic nerve causes vision changes such as:
- Color desaturation
- Blurry or dim vision in one eye
- Pain during eye movement
It’s often associated with multiple sclerosis, but can also occur due to infections or autoimmune conditions.
Retinal Disorders
The retina is home to cone cells responsible for color detection. If one eye develops a retinal condition, like macular degeneration, diabetic retinopathy, or retinal detachment, the resulting condition may disrupt color vision in that eye.
Stroke or Brain Injury
In rare cases, differences in color perception may result from neurological conditions. Damage to areas of the brain that process visual input—such as the occipital lobe—can impact how color is interpreted, even if the eyes themselves are healthy.
Medication Side Effects
Some medications can affect color vision as a side effect. In rare instances, these effects may appear in only one eye if the impact is uneven or related to pre-existing conditions. Drugs linked to color vision changes include:
- Digitalis (used for heart conditions)
- Certain antipsychotics or antidepressants
- Ethambutol (used for tuberculosis)
Ocular Trauma or Surgery
A past injury or surgery affecting one eye could lead to scarring, nerve damage, or other complications that affect color processing.
How Is One-Eyed Color Blindness Diagnosed?
Diagnosis begins with a comprehensive eye exam, where your optometrist will evaluate both eyes for any noticeable differences in vision, structure, and color perception.
Color Vision Testing
The most common test for color blindness is the Ishihara test, which uses dot-patterned plates to assess how well you can distinguish numbers or shapes in various color combinations. When testing one eye at a time, your optometrist can identify if the issue is isolated.
Additional Diagnostic Tools
If a difference is detected between your eyes, further testing may be recommended to find the root cause:
- Visual field testing (to detect nerve or brain-related issues)
- OCT scans (to assess retinal health)
- Color contrast sensitivity tests
- Neurological imaging (in select cases)
The goal is to rule out serious conditions and determine whether the color vision loss is reversible or permanent.
Is One-Eyed Color Blindness Treatable?
Treatment depends entirely on the underlying cause.
- If caused by optic neuritis, corticosteroids or immune treatments may reduce inflammation and restore vision.
- Retinal issues may require laser therapy, injections, or surgical intervention.
- If a medication is responsible, switching prescriptions could resolve the issue.
- In some cases—particularly when damage is permanent—management may focus on adapting to the change rather than reversing it.
For people with lasting vision differences, tools like color-correcting lenses or apps that enhance color perception on digital devices may help improve quality of life.
What If It’s Not Color Blindness?
Sometimes, what feels like “color blindness” is actually a change in light sensitivity, visual clarity, or contrast perception. Cataracts, for example, can cause one eye to perceive colors as dull or yellowed.
Any noticeable difference in how your eyes perceive the world—especially when it affects just one side of your vision—should be evaluated. You might not be experiencing true color blindness, but your eyes still deserve attention.
When to See an Optometrist
If you notice any of the following in one eye, it’s time to book an appointment:
- Colors appear faded, dull, or different from the other eye
- Recent eye injury or vision change
- Blurry vision, especially with light sensitivity
- Headaches, dizziness, or eye pain
- Trouble identifying certain colors during daily tasks
Early diagnosis and treatment are key to protecting your vision and ruling out more serious conditions.
Your Partner in Color Blindness & Vision Care
Color blindness in one eye is rare, but it’s not something to ignore. Whether the cause is neurological, retinal, or medication-related, changes in color perception can signal something deeper about your eye or brain health.
The good news? With prompt attention and a thorough eye exam, many causes can be diagnosed—and in some cases, treated—before lasting damage occurs.
At Riverside Optometry in Riverside, CA, we take vision changes seriously. If you’re noticing a difference in how each eye sees color, our team is here to help. We’ll walk you through a complete exam, explain your results, and ensure you get the care and clarity you deserve.
Book your eye exam today and get clear answers for your color vision concerns.
