WEDNESDAY, Oct. 11 (HealthDay News) -- Hearing and vision loss often occur together in older adults, an Australian study finds.

The study of over 1,900 adults averaging about 70 years of age found that those with vision loss were more likely to also have hearing loss, and vice-versa.

Among the people in the study, 178 (9.3 percent) had visual impairment (worse than 20/40 vision) without glasses or contact lenses, and 56 (2.9 percent) had best-corrected visual impairment. This means that their best vision while wearing glasses or contact lenses was still worse than 20/40.

There were 766 (40 percent) people with hearing impairment, including 599 with mild impairment, 141 with moderate impairment, and 26 with marked impairment.

Of the 178 people with visual impairment, over 65 percent had hearing loss. For each additional line on the eye chart that a person could not read, the odds of hearing impairment increased by 18 percent if the sight reduction was in best-corrected vision or 13 percent in uncorrected vision, the study said.

After further investigation, the researchers concluded that cataracts and age-related macular degeneration -- the two most common causes of vision loss in older people -- were both independently associated with hearing loss.

The study authors suggested a number of reasons for this link between vision and hearing loss. Both conditions are regular consequences of aging and both share common risk factors, including smoking, hardening of the arteries, and diabetes.

"Further studies are needed to understand the relationship between visual and hearing impairments in older persons and to determine whether intervention to improve these impairments could delay biologic aging," the researchers wrote.

The study was published in the Oct. 9 issue of the journal Archives of Ophthalmology.

More information

The U.S. National Institute on Aging has more about eyes and aging.