So spare a thought for the advocates for hearing and eyesight. These two health areas that are vital to the health and wellbeing of all Australians and to the Australian economy not only never get a mention in campaigns - they never get a mention.

It's as if the healthcare system has excised the head from the rest of the human body. Mental and dental health struggle for integration within the current system and hearing and sight are completely forgotten.

Yet, every day, millions of Australians struggle to learn, to work, to communicate and to be part of society because they have poor hearing or poor eyesight. We don't accurately know how many people are affected because the data has not been updated in some time, a sure sign of where they sit on the list of policy priorities.

Currently about one in six Australians is affected by hearing loss and by 2050 this is expected to rise to one in four.

More than half of the population aged 50 and over has hearing loss, and it's more common in farmers, people who have been in the military, people who have diabetes, and Indigenous Australians.

In 2005 it was estimated that hearing loss cost the Australian community about $11.75billion or 1.4 per cent of GDP every year, with lost productivity ($6.7billion) as the major component of this cost. An estimated 160,000 Australians are not working because they can't hear well enough.

Despite the ubiquity of hearing loss and the heavy burden it imposes, it is an invisible disability that carries a stigma, so many people don't reach out for treatment and help.

In 2009 it was estimated that about 300,000 Australians had substantial vision impairment, with around 20,000 being totally blind. These figures could be much higher; about 10 per cent of the population aged over 55 years is estimated to be visually impaired.

The overall incidence of blindness and vision impairment in Australia is predicted to grow by 50 per cent over the next decade as the population ages and the incidence of diabetes-related eyesight problems grows.

Indigenous Australians have six times the rate of blindness and three times the rate of low vision as other Australians.

The costs of this play out in many ways. People who are blind or have low vision are four times more likely to be unemployed compared to the general population. Visual impairment is the cause of many falls and injury in older people. It's estimated that in Australia 116,000 people refer to a hospital or general practitioner each year with eye injuries.

Economic analysis undertaken by Access Economics put the total cost of vision disorders in Australia in 2004 at $9.85billion annually. Together these two health areas cost Australia and Australians more than $22billion every year. With much of this burden amenable to prevention or treatment, it's time for some active investments to address this cost.

For example, 75 per cent of vision loss is entirely avoidable through prevention or treatment. The Access Economics study revealed that implementation of eye care interventions costing about $190million (equivalent to 10 per cent of the direct health costs of vision impairment and just 0.23 per cent of total health expenditure in 2005-06) could realise financial savings of more than $650million.

Moreover, up to 11 per cent of the burden of vision impairment could be averted in the first year if this was done in a concerted fashion.

An improved focus on health ageing and tackling preventable disability may provide the mechanism to get an increased focus on hearing and sight.

The healthcare and occupational health and safety systems must be geared to preventing hearing and sight loss wherever this is possible, to screening and early intervention to provide treatment and remedies without delay, and to recognition of the mental health impacts and physical health issues associated with the loss of these important faculties.

There is very little ''low-hanging fruit'' left in healthcare, but here are examples of where smart investments can yield real and cost-effective benefits very quickly. It's time hearing and sight were heard and seen on the healthcare agenda.

Dr Lesley Russell is a research associate at the Menzies Centre for Health Policy, University of Sydney.