Many people would be dubious about the idea of spending a few weeks walking across the Arctic icecap. Spending all your waking hours pulling a 60kg supply sled over inhospitable and gruelling terrain (nothing like as flat as most people imagine) hardly seems enticing. With temperatures rarely above -20C, nerve damage to your extremities is almost guaranteed and there's the constant danger of falling through the ice into paralysingly cold water. Throw in the cruel reality that the icepack's drift can literally have you going backwards, and the idea might seem like sheer lunacy.

But for me, my mates Dave Jessop, Alex Moore and Steve Wright, and our guide, Czech adventurer Miroslav Jakes, the idea of an unsupported expedition from the 89th parallel to the geographic North Pole and back made perfect sense. As one of the few places on the planet that humans have not tamed, the far northern Arctic epitomises wilderness in its purest, most unapologetic form. It was the desire to experience such wilderness, with its serene beauty and savage mood swings, which underpinned all of our various reasons for embarking on the journey.

Our Start and finish point was to be Borneo Ice Base, a temporary camp that hardly group of explorers and scientists set up every April in the Russian sector of the Arctic. But when the cargo plane that had flown us from Longyearbyen in Norway landed at the ice base, we learned that it was not exactly at the 89th parallel but slightly closer to the pole thanks to the drift of the ice. As the plan was to cover a full degree of latitude on our way to the Pole, we decided to arrange for a chopper to drop us off right on the 89th.

At these last northerly degrees of latitude, the unforgiving forces of nature reign supreme, making survival an incessant struggle. Here, surrounded by hundreds of kilometres of frozen sea, we were mere specks of protoplasm in a barren white ocean, uncompromising forces dictating our every move. As we stood on the 89th parallel, watching the chopper disappear into the distance, this sobering reality hit home. The next few weeks would be a test of how we could contend with these forces.

Coping with cold

The most obvious challenge confronting us was the cold of course. But while we knew what to expect and had prepared for bone-numbing temperatures, we didn't truly appreciate how profoundly cold it would be until we were on the icepack. For the first few days, Mother Nature pulled out all of the stops, taking the temperatures down as low as -45C - and that's without much of a wind-chill factor. In case we were tempted to discount the wind, on our second day a ferocious gale whipped up mini-twisters of snow, and we learnt about wind-chill the hard way.

It was miserable. Our eyes and noses ran constantly, eyelashes freezing together and small stalactites of snot forming under our nostrils. Our breath froze in front of our faces, leaving vertical halos of ice crystals on our hoods.

On days like these we could scarcely stop for more than a couple of minutes to gobble down a chocolate bar or some raw smoked bacon strips before our body temperatures plummeted to potentially hypothermic levels. The only solution was to keep moving, to keep the blood flowing in the hope that it would eventually bring some feeling back into our fingers and toes. As the expedition photographer, this was the hardest part of the trip for me, trying to document our journey, gripping the frigid metal body of my camera with the cold penetrating my glove liners. A couple of times the numbness lasted so long I began to panic, banging my fists together and punching my sled in frantic attempts to get the blood back into my fingertips.

Getting the drift

Another of nature's forces we could never ignore was the near-constant drift of the icepack, which often determined the pace of our progress. Depending upon the prevailing winds, this drift would either pull us towards - or away from - our destination.

Soon after we started walking away from the 89th parallel, we discovered that the ice was moving northeast at an alarming rate. This was something our training had not prepared us for; navigating by GPS in the hills of Hong Kong, it was simply a matter of moving from one fixed point to another. But on the Arctic ice, navigation is all about plotting a course and then adjusting it to compensate for the drift.

Fighting the drift was futile. As we man-hauled heavy sleds over the uneven surfaces, our progress was far too slow to "outrun" the movement of the ice. The trick was to keep shifting course to benefit from - or at least to offset - the icepack's flow. In this case, the northeasterly drift forced us to take an almost entirely westward course to avoid overshooting the Pole altogether, which would have had us winding up in the Canadian sector. Though we knew this accommodation in our course was the right thing to do, it was hard to get our heads around the idea of heading due west in an effort to reach the most northerly point on earth.

Handling the pressure

Further complicating our progress were the so-called "pressure ridges": often-giant hills of ice slabs that are formed when plates of ice collide and compress against each other. Watching these miniature mountain chains forming was like having an accelerated lesson in plate tectonics - one best viewed from a respectful distance.

These pressure ridges quickly became the bane of our existence, invariably grinding our ski-cald caravan to a near-halt as we carefully tried to creep our way over them. Hour upon hour was spent struggling to drag our sleds up and over enormous mounds of ice blocks while maintaining our footing on the slippery surfaces. Inch by hard-fought inch, we stumbled our way over, straining against taut ropes as we pulled our sleds to the top, only to have them come crashing down on us on the other side. Ankles were turned. Fingers were smashed. Skis and poles were jettisoned in furious foot-scrambles over the biggest ice blocks. Curse after heartfelt curse was uttered.

Of course, no amount of anger or brute force could speed up our progress past these barriers, and we had to acknowledge that getting angry was nothing but a waste of energy. The pressure ridges were there to stay, and we were going to have to adapt to them if our expedition was to be successful. It was better to take our time, ponder each step, improve our hauling techniques - and try to laugh when one of us went tumbling.

Finally, after eight days of tough man-hauling, we reached the Pole. It was here that the spectacular drift of the ice was most obvious, for we found we could only stand at 90 for a fleeting moment before the ice had moved us away from it again. To stay exactly at the Pole we had to keep sidestepping against the direction of the drift.

We pitched camp and took a much-needed rest day, but by the time we were ready to head back towards the ice base, the drift had already carried us several kilometres from the Pole and into the Canadian sector of the Arctic.

Cracking up

It was here that the fun really began. With the temperature getting slightly warmer each day - one day rising as high as -12C -the ice was melting faster and breaking up presenting us with a new set of challenges.

From here on out our biggest concern was to avoid falling through the ice into the ocean - a disaster that could quickly lead to severe frostbite or even death. As Dave never hesitated to remind us: "Lads, just remember, if you fall in there it's four kilometres to the bottom." These words were at the forefront of our minds as we made our way across long patches of thin "Black" ice and cautiously crept over cracks with narrow channels of dark water - called "leads" in Arctic parlance - flowing underneath our feet. When the leads were too wide, we had to track along them.

A worthy cause

Back in Hong Kong, we still had a vital part of the expedition left - collecting the money we had raised for a new project Orbis eye-care centre in Xiangyun County, near Dali in China's Yunnan Province. To date we have collected just over HK$148,000 (US$19,000) which will buy five pieces of diagnostic and surgical equipment.

About 0.8% of Xiangyun's population of 430,000 is blind, with some 50% of these cases caused by cataracts - one of the most preventable and treatable causes of blindness. Eye-care coverage in the county is exceptionally weak, even compared with that of other remote areas of China. For this reason, Obis is establishing a prototype facility - a departure from their core focus on training eye doctors from developing countries in basic surgical procedures - to ultimately be run jointly by the provincial Red Cross hospital and the Xiangyun County hospital. We are proud to have been able to contribute some of the equipment that will allow them to use the centre to its full potential.