KUALA LUMPUR, March 23 — Men are more likely to experience colour vision deficiency (colour blindness) than women, in line with the principles of Mendelian genetics.
Universiti Kebangsaan Malaysia (UKM) Community Health Research Centre’s Optometry and Vision Science Programme senior lecturer Rokiah Omar said this is because the gene responsible for producing photopsin (colour pigment) is located on the X chromosome, while men only have one such chromosome.
She explained that any defect in the gene controlling photopsin will result in colour vision deficiency being physically expressed.
“Colour blindness can also be inherited from parents. For example, if the father is normal and the mother is a carrier, 50 per cent of sons are at risk of being colour blind, while 50 per cent of daughters may become carriers,” she told Bernama recently.
The low vision specialist added that about 4.8 per cent of men in Malaysia have congenital colour blindness (from birth), consistent with global trends estimating that about eight per cent of men and 0.5 per cent of women worldwide are affected.
Dr Rokiah explained that medically, congenital colour blindness is classified as a colour vision deficiency caused by genetic mutations in the retinal cone cells, rather than an infectious disease. However, it can also be acquired as a result of other chronic conditions.
Although not life-threatening, Dr Rokiah stressed that the condition significantly impacts economic mobility, as it affects daily functioning and safety, including difficulty distinguishing traffic lights, assessing food ripeness, or reading colour indicators on household devices. — Bernama pic
“Uncontrolled diabetes mellitus can damage blood vessels in the retina, affecting cone cell function responsible for colour perception. Glaucoma, cataract, muscular degeneration, as well as certain medications that are toxic to the optic nerve, may also cause temporary or permanent colour blindness,” she said.
She added that public awareness of colour blindness still needs improvement, as many individuals only discover their condition after failing eye tests for driving licences or job applications.
Although not life-threatening, Dr Rokiah stressed that the condition significantly impacts economic mobility, as it affects daily functioning and safety, including difficulty distinguishing traffic lights, assessing food ripeness, or reading colour indicators on household devices.
“It also limits career choices, as colour blind individuals cannot enter fields requiring precise vision such as pilots, electrical engineers, pharmacists and security personnel,” she said.
Dr Rokiah noted that participation in Technical and Vocational Education and Training (TVET) is also limited, as courses such as electrical, electronic, mechanical and civil engineering require normal colour vision to differentiate wire colours or circuit symbols, to avoid risks such as explosions or short circuits.
This has caused some technically inclined students to shift to other fields due to inherited colour blindness, creating a gap in national human capital development in Science, Technology, Engineering and Mathematics (STEM), she said.
“However, students with colour blindness still have opportunities to pursue studies in fields that do not rely heavily on critical colour recognition,” she added.
She also called for better alignment between school screening systems and the job market to ensure students are not trapped in career aspirations that are unattainable.
Data from school health programmes by the Health Ministry and Education Ministry show an increase in colour blindness cases since 2013. However, she said this should not be interpreted as a “clinical epidemic,” but rather reflects the effectiveness of more comprehensive screening using the Ishihara Test.
On visual aids, she said there are special contact lenses or glasses such as ChromaGen that can help enhance colour contrast, although their cost is relatively high.
Meanwhile, a teacher at Sekolah Kebangsaan Sungai Anak Selangau in Sarawak, Helmi Ali, 28, who inherited colour blindness from his mother, said early screening should be conducted as early as preschool level.
He said he was diagnosed with colour blindness at the age of nine or 10 after being reprimanded by his art teacher, who initially thought he was not putting effort into colouring.
“When people talk about colour blindness, many assume I can only see in black and white. That perception needs to be corrected because colour blind individuals can still see like normal people, but have difficulty distinguishing certain colours.
“Last year, when everyone was buying Hari Raya outfits based on a theme, my mother and I bought green instead of brown. That’s why when we shop for clothes, we go with my sister who has normal vision,” he said.
Sharing his driving challenges, he said he relies on memory of traffic light positions, although more traffic lights with countdown timers are now being introduced in Sarawak. — Bernama