The researchers have found a unique way to analyze association between air pollution and higher risk of heart disease just by looking into tiny blood vessels in a person's eyes.

The findings of the study appeared in journal PLoS Medicine. The research discovered that the new digital photos of the retina reflect that if the retinal arterioles of a healthy person exposed to high levels of air pollution are narrower then he/she is at a greater risk of having a heart disease.

The study suggests that people who are exposed to shorter-term low level of pollution have their microvascular or tiny blood vessels as similar to that of a three years old child. But, those, who remain in polluted air for longer period, have their blood vessels of seven years old.

Sara Adar from the University of Michigan School of Public Health said, "Such a change would translate to a three percent increase in heart disease for a woman living with high levels of air pollution as compared to a woman in a cleaner area".

The study involved 4,607 people aged 45 to 84 and having no association with heart disease. The digital retinal photographs of their blood vessels were taken and the air pollution levels in their homes for two years before the eye test were assessed.

It was found that the levels of air pollution had a negative impact on blood vessels that could lead to cardiovascular events such as heart attacks.