Last updated:
5/5/26
Years published: 2026
NORD gratefully acknowledges the following for the preparation of this report: Sara Gerber, MS, Emily Kohl, MS, Jannina Mock, MS; Stanford’s Master’s Program in Human Genetics and Genetic Counseling, as well as Aiste Narkeviciute, MS, CGC, Stanford Master’s Program in Human Genetics and Genetic Counseling, and review by Susanne Kohl, PhD, Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen.
Summary
Achromatopsia is a rare genetic condition that causes differences in the way the eye processes light and color. The most common symptoms of achromatopsia include blurry or hazy vision (severely reduced visual acuity), reduced or absence of color discrimination (color blindness), increased sensitivity to light (glare/photophobia), a central blind spot (scotoma), involuntary, smooth, back-and-forth eye movements (pendular nystagmus), and focusing on objects using the side of one’s vision (eccentric fixation). 1
This condition affects fewer than 1 in 30,000 people. Most individuals have complete achromatopsia (also called rod monochromacy or monochromatism), meaning they are unable to see any color. Rarely, individuals have incomplete achromatopsia; they can see some color.2
Symptoms start in the newborn period. The condition is generally stable (non-progressive).
Achromatopsia is caused by genetic changes (pathogenic variants) in the ATF6, CNGA3, CNGB3, GNAT2, PDE6C, or PDE6H genes. Inheritance is autosomal recessive.1
It is recommended that individuals with achromatopsia see a specialist eye doctor (ophthalmologist) every 6 to 12 months in childhood and every 2 to 3 years as adults.
Some signs and symptoms of achromatopsia develop within the first few weeks of life. Involuntary eye movements are usually the first noticeable sign, followed by light sensitivity. The condition is generally non-progressive, so symptoms do not get worse over time. Common signs and symptoms include:1
Sometimes there can be changes to the back of the eye (macula) that can be seen on imaging of the eye (optical coherence tomography). These changes can progress over time.
Achromatopsia can be complete or incomplete. Incomplete achromatopsia is rare compared to the complete form of the condition. Complete achromatopsia occurs when all three types of cone cells in the eye (red, green, and blue-sensitive cones) do not function properly. Incomplete achromatopsia occurs when one or more cone types function partially. Symptoms are similar, but usually less severe for people with incomplete achromatopsia.1, 2
Achromatopsia is caused by disease-causing changes (pathogenic variants, formerly called “mutations”) in genes that create proteins needed for the cone cells to work properly. In our eyes, we have cells called rod cells and cone cells. Cone cells are responsible for daylight and color vision, as well as high acuity vision (seeing detail/sharply). Cone cells detect light through a process called phototransduction, which converts light into electrical signals that the brain can understand. Typically, when light enters the eye and hits a cone cell, it activates special light-sensitive proteins. These proteins create a chain reaction to reduce the amount of a chemical messenger called cGMP inside the cone cell. When cGMP levels drop, the electrical charge of the cell changes. This creates a signal that travels through the light-sensitive tissue at the back of the eye (retina) to the brain, allowing us to see. When genes involved in phototransduction (such as CNGA3, CNGB3, GNAT2, PDE6C, PDE6H) do not work properly, this process breaks down. Up to 90% of the people affected with achromatopsia have variants in either CNGA3 or CNGB3. 1, 3-5 In addition, variants in ATF6 can also cause achromatopsia, although this protein is not involved in the phototransduction cascade; why this gene can cause achromatopsia is not yet fully understood.
Inheritance
Achromatopsia is inherited in an autosomal recessive manner. Recessive genetic disorders occur when an individual inherits a disease-causing genetic difference in the same gene from each parent. If an individual receives one normal gene and one disease-causing genetic difference, the person will be a carrier for the disease but usually will not show symptoms. The risk for two carrier parents to both pass the genetic difference and have an affected child is 25% with each pregnancy. The risk of having a child who is a carrier is 50% with each pregnancy. The chance for a child to receive normal genes from both parents is 25%. The risk is the same for males and females.
Achromatopsia is the most common cone dysfunction disorder and affects about 1/30,000 people.2 Males and females have equal chances of being affected. This disorder becomes apparent within the first few weeks after birth, and symptoms remain present throughout life.
A clinical diagnosis can be established based on observed symptoms through a series of eye tests. These tests include visual acuity tests, which evaluate how well the individual can see, color vision tests to evaluate colorblindness, visual field testing to look for blind spots (scotomas), an electroretinogram to examine the eye’s response to light, and various other scans and imaging (optical coherence tomography, fundus autofluorescence imaging, adaptive optics imaging) to look at the structure of different parts of the eye. Clinical signs that help diagnose achromatopsia include: 1
Genetic testing is available to support the clinical diagnosis. Molecular testing should include sequencing of all 6 genes associated with achromatopsia (ATF6, CNGA3, CNGB3, GNAT2, PDE6C, PDE6H). Today, it is recommended to include all genes associated with other eye disorders, especially if some clinical findings do not match achromatopsia, or if the affected person is too young to assess for certain features. 1, 5, 6
Clinical Testing and Work-Up
Standard clinical eye (ophthalmologic) evaluation and testing, color vision evaluation, and consultation with a geneticist and/or genetic counselor are recommended.
Additional testing to evaluate clinical features of achromatopsia may be performed.
As individuals with achromatopsia may lack color discrimination, color vision tests may be performed to test the specific impairments for color discrimination. The red-green color discrimination test can serve as an important diagnostic test.
Other vision testing may include visual field testing, an electroretinogram, optical coherence tomography, fundus autofluorescence imaging, and adaptive optics imaging. These different types of tests can provide more information about abnormalities in eye anatomy and function, including central visual field defects and cone dysfunction.
There are currently no approved treatments for achromatopsia; treatment of manifestations is the primary care that is offered. Special filter glasses, dark glasses, or red-tinted contact lenses may reduce sensitivity to light and thus improve the clarity of vision (visual acuity). Magnifiers (tools designed to enlarge text and objects for the user) may be useful for reading or using devices. In classrooms, children with achromatopsia should be placed in the front and away from windows to reduce glare. Other low vision aids may be useful. 1, 6, 7
Information on current clinical trials is posted on the Internet at https://clinicaltrials.gov/
All studies receiving U.S. Government funding, and some supported by private industry, are posted on this government website. For information about clinical trials being conducted at the NIH Clinical Center in Bethesda, MD, contact the NIH Patient Recruitment Office:
Tollfree: (800) 411-1222
TTY: (866) 411-1010
Email: [email protected]
Some current clinical trials also are posted on the following page on the NORD website: https://rarediseases.org/living-with-a-rare-disease/find-clinical-trials/
For information about clinical trials sponsored by private sources, contact: http://www.centerwatch.com/
For information about clinical trials conducted in Europe, contact: https://www.clinicaltrialsregister.eu/
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The Genetic and Rare Diseases Information Center (GARD) has information and resources for patients, caregivers, and families that may be helpful before and after diagnosis of this condition. GARD is a program of the National Center for Advancing Translational Sciences (NCATS), part of the National Institutes of Health (NIH).
View reportOrphanet has a summary about this condition that may include information on the diagnosis, care, and treatment as well as other resources. Some of the information and resources are available in languages other than English. The summary may include medical terms, so we encourage you to share and discuss this information with your doctor. Orphanet is the French National Institute for Health and Medical Research and the Health Programme of the European Union.
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