R R

What Percentage of Color Blindness Cases Are Acquired, Not Genetic?

While precise global statistics are difficult to isolate due to under-reporting, it is established that the vast majority of color vision deficiency (CVD) is genetic (Congenital), affecting approximately 8% of males and 0.5% of females. By comparison, acquired color blindness is statistically much rarer in the general healthy population but becomes significantly prevalent in elderly and clinically ill populations. Studies indicate that nearly 15% to 20% of patients with chronic systemic diseases (like diabetes or multiple sclerosis) develop some form of acquired color discrimination loss over their lifetime.

Link to This Resource Page

Provide a valuable resource to your clients or customers by linking to this resource page. Just place the following link on your website.

To display this...

What Percentage of Color Blindness Cases Are Acquired, Not Genetic?

While precise global statistics are difficult to isolate due to under-reporting, it is established that the vast majority of color vision deficiency (CVD) is genetic (Congenital), affecting approximately 8% of males and 0.5% of females. By comparison, acquired color blindness is statistically much rarer in the general healthy population but becomes significantly prevalent in elderly and clinically ill populations. Studies indicate that nearly 15% to 20% of patients with chronic systemic diseases (like diabetes or multiple sclerosis) develop some form of acquired color discrimination loss over their lifetime.

read more about acquired color blindness statistics ...

Copy this HTML:

Copy HTML Copied!

Genetic vs. Acquired: The "Rule of Thumbs"

Distinguishing between a birth defect and a medical symptom is critical. Clinical guidelines distinguish them using three main criteria:

Laterality. Genetic defects almost always affect both eyes equally (bilateral). Acquired defects often affect one eye more than the other (asymmetric) or are strictly monocular.

Stability. Genetic defects are constant throughout life; they do not get better or worse. Acquired defects are progressive; they can fluctuate, worsen with disease, or improve with treatment.

Axis. Genetic defects are predominantly Red-Green (Protan/Deutan). Acquired defects can be Red-Green or Blue-Yellow (Tritan).

Kollner's Rule (Predicting the Cause)

Ophthalmologists use a heuristic called Kollner’s Rule to determine where the damage is located based on which colors are missing:

Blue-Yellow Defects (Tritan). Usually indicate damage to the outer retina or the optical media. Common causes include Age-Related Macular Degeneration (AMD), Diabetic Retinopathy, Cataracts, and Glaucoma.

Red-Green Defects (Protan/Deutan). Usually indicate damage to the inner retina or optic nerve. Common causes include Optic Neuritis, Multiple Sclerosis, and compressive tumors.

Drug Toxicity (Hydroxychloroquine)

One of the most clinically monitored causes of acquired color blindness is pharmaceutical toxicity. Medications such as Hydroxychloroquine (Plaquenil), used for Lupus and Rheumatoid Arthritis, can bind to retinal pigment. The first sign of toxicity is often a subtle loss of color vision (specifically red targets) before black-and-white visual acuity is affected. This is why patients on these drugs undergo annual color testing.

Chemical Exposure (Solvent Dyschromatopsia)

Occupational health data shows that chronic exposure to industrial chemicals can strip color vision. Workers exposed to high levels of organic solvents such as styrene, toluene, and carbon disulfide have a documented risk of developing acquired Blue-Yellow color loss. This "Solvent Dyschromatopsia" is dose-dependent and can sometimes be partially reversed if exposure ceases early.

FAQs on Acquired Defects

Can cataracts cause it?

Yes. As the natural lens yellows with age (nuclear sclerosis), it acts like a blue-blocking filter. This absorbs blue light, causing a mild "tritan" (blue-yellow) defect. Patients often report seeing colors significantly "brighter" and "bluer" immediately after cataract surgery.

Will Ishihara plates detect it?

Often, no. The standard Ishihara book (dots with numbers) is designed strictly for genetic Red-Green defects. It often completely misses Blue-Yellow acquired defects. Doctors must use the HRR (Hardy-Rand-Rittler) test or the Farnsworth D-15 sorting test to catch acquired issues.

Is it reversible?

Sometimes. If the cause is a cataract, surgery fixes it 100%. If the cause is optic neuritis (swelling), color vision often returns as the swelling goes down, though it may look "washed out" (desaturated) permanently.

When to See Your Eye Doctor

If you have always had normal color vision and suddenly notice that colors look "washed out" in one eye, or if you cannot distinguish between navy blue and black socks anymore, this is a medical red flag. Unlike genetic color blindness, which is harmless, this symptom can indicate active optic nerve disease or toxicity.

References

https://www.aao.org/education/image/kollners-rule https://pubmed.ncbi.nlm.nih.gov/11322744/ https://www.ncbi.nlm.nih.gov/books/NBK10892/ https://eyewiki.aao.org/Acquired_Color_Vision_Deficiency