By Matthew Davis With Raleigh International in Ghana

Rama had barely seen the world for 20 years, but as she removed the bandages from around her eyes her face lit up with fascination and disbelief.

The 73-year-old's amazement at the transformation was a world away from the fear that had gripped her two days before as she lay in an operating theatre awaiting eye surgery.

Most of the people had walked for a day just to get to the clinic to have their eyes tested

Helen Wilson, Raleigh International

Earlier that week, she had risen at 4am and walked for more than six hours to queue with hundreds of others at an eye screening clinic in a village near Keta, on Ghana's south-east coast.

It is thought 80% of the world's blindness is avoidable, with about seven million people becoming blind every year, nine out of 10 of them in developing countries.

Songs for success

Poverty is the greatest obstacle to treatment, said Dr Divine Ameho, who worked on the two-week eye clinic sponsored by UK-based charity Sight Savers International.

An eye operation costs up to �1,000 and the clinics provide an invaluable chance for treatment for people who would normally have to struggle on with treatable sight problems like cataracts.

Cataract removal takes 30 minutes

The scores of people that queued for treatment were testament to the need.

The eye tests were basic. Patients held their hand over one eye and read a simple chart.

If their vision was bad, they were referred to a doctor who then gave them an appointment for the 30-minute operation needed to restore their sight.

'Inspiring'

The clinics were staffed by young volunteers from the UK and Ghana as part of a Raleigh International expedition.

Many said the profound effect the screening and the subsequent surgery had on the lives of the patients, was a "humbling" experience for them.

Helen Wilson, one of the expedition's administrators, said: "The amazing queues of people - and their inspiring welcome - on our first day of work will stay in the memory forever.

Eye disease

The three major causes of blindness are cataracts, trachoma and onchocerciasis Cataract is a cloudiness of the lens of the eye, which stops light entering and eventually leads to loss of sight Trachoma is caused by a micro-organism, which spreads through contact with eye discharge from the infected person and through transmission by eye-seeking flies Onchocerciasis is often called river blindness because the black fly that transmits the disease abounds in riverside areas

"Some villages we visited were in the middle of nowhere and most of the people had walked for a day just to get to the clinic to have their eyes tested.

"Most of those queuing were more than 60 years old."

Back at Keta Hospital, the volunteers were able to watch surgeons remove the cataracts and - with a 99% chance of success - anxiously awaited the removal of bandages over the next 48 hours.

Miss Wilson said: "The effects were incredible.

"People were stunned, they could barely believe what had happened to them."

The two-week programme screened more than 3,000 people - sponsored by Sight Savers at a cost of about �8,000.

The charity is one of the founder members of Vision 2020 - a World Health Organisation initiative to prevent an additional 100 million people from going blind by the year 2020.