A new study from China revealed that older adults suffering from cataracts are also more likely to develop symptoms of depression.

The study, published in the journal Optometry and Vision Science, showed a strong link between visual impairment and depressive symptoms, with the link appearing to be strongest among older adults with lower education.

"[O]ur study sheds further light on the complex relationship between aging, vision loss, cataract, and depression and suggests that there may be a role for cataract surgery in improving mental health in the elderly," the researchers wrote in a press release.

For the study, the researchers conducted a community-based survey of 4,611 Chinese adults aged 60 years or older. The researchers asked the participants to complete a depression questionnaire. Using Lens Opacities Classification System (LOCS) III scheme, the age-related cataracts of the participants were clinically graded.

Among the participants, about 49 percent of the older adults had cataracts in at least one eye, excluding those with previous cataract surgery. About eight percent of the participants had depressive symptoms based on the 9-item Patient Health Questionnaire (PHQ-9) depression scale.

The researchers observed that symptoms of depression are 33 percent more likely to people suffering from cataracts, with the risk of depressive symptoms similar for subjects with cataracts in one versus both eyes. Furthermore, the risks of depressive symptoms were 50 percent higher in older adults with no formal education. Taking other factors into account, cataracts explained 14 percent of the variation in depression risk.

No direction of association can be formally established with the present study. The researchers noted that cataracts, leading to vision loss, might be forcing older adults to become isolated or withdrawn. It is also possible that depression might be making the older adults less likely to seek treatment for their cataracts.

According to the Centers for Disease Control and Prevention, about 16 percent of people in the United States, or 20.5 million Americans aged 40 years and older have cataracts.