Nick Love is very fond of rugby. So when he planned a trip to watch the British Lions play on their recent three-week tour of New Zealand, he was extremely concerned that he would have to miss some of the games because of jet lag. “With the time difference plus the 22-hour flight I thought I was going to feel terrible for four to five days,” he says.

Love, who works for a software company, came across an advertisment for a light-emitting visor which is said to help you adjust to a new time zone by slowing down the body’s internal clock. “I had my doubts, but thought I’d give it a go.” The visor looks like a plastic version of the sun protector once favoured by tennis players, but with lights, rather than terry towelling, under the brim. Love put his usual bed time and the time zone he was travelling to, into a jet lag calculator, which then told him precisely when he should wear the visor — in two three-hour stints on consecutive days. The first of these occurred on the flight to Toyko; at 2am British time, Love and his friend switched on their visors. “The cabin was dark, so in order not to disturb anyone we put blankets over our heads and read,” he says. “We got some funny looks and some of the airline staff asked us what we were doing. It felt a bit unnatural, but it wasn’t uncomfortable — it was like having a standard lamp over your head.”

The experiment paid off. After another session when he arrived in New Zealand, Love had a good sleep and woke up “fresh as a daisy”. “I had no problems with wanting to sleep during the day and I didn’t feel washed out and listless in the way I have with jet lag before. It was as though I’d taken a trip to Dublin.”

The company that supplies the visor has traditionally sold its products to sufferers of seasonal affective disorder. “Light therapy” is increasingly being investigated, however, as a potential remedy for the physiological distress caused by jet lag.

Dr Chris Idzikowski, an expert in sleep therapy at Edinburgh University, explains: “The biological clock is like the conductor of an orchestra. Light therapy is a way of getting the conductor on side, which should mean the systems it controls adjust rapidly too.”

Dr Idzikowski has recently been employed by British Airways to find ways of helping passengers to sleep better and to reduce the effects of jet lag. Over the next eight months, he will research a range of sleep technologies, including light therapy. On a flight to New York, he explains the difficulties faced by all airlines in making the long-haul travel experience more comfortable.

“For a start, there’s the mechanical problems: at 8,000ft the oxygen level is lower than on the ground despite the pressurised cabin, and this affects your ability to sleep. The air is also drier than on the ground, so there’s a degree of dehydration. It’s harder to fall asleep vertically rather than horizontally. Then there’s the meal, the movies, the entertainment, the whole in-flight service which disrupts passengers’ ability to get to sleep.

“Jet lag is partly due to the eight-hour flight itself,” says Dr Idzikowski. “But mostly it occurs because your internal clock is out of kilter.” The body clock is a clump of 20,000 nerve cells in the brain which control a range of body processes over a 24-hour period by responding to external signals, such as sunlight.

“It’s not just sleep; mental alertness, joint flexibility, muscle efficiency and mental performance are all affected. The clock also controls things like the production of water by your kidneys, a process that is usually slowed down at night-time, which is why one of the problems associated with jet lag is wanting to go to the loo at the wrong times. It also secretes an appetite suppressant hormone, so in a jet lag situation you’re more likely to feel hungry when you shouldn’t.”

All these effects, Dr Idzikowski hopes, can be countered using light therapy — either in the form of controlled cabin lighting, or individual aids such as the Deluxe Visor.

A breakthrough in jet lag prevention came when researchers at Northwestern University, Evanston, Chicago, discovered a third kind of light receptor in the retina which feeds straight into the body clock and which may influence mood and performance. This light-sensing system is more receptive to light at the blue end of the spectrum, “so it could be that adding a blue tint to the lighting has an impact”, says Dr Idzikowski.

By exposing someone to bright light just before their clock would usually reach its slowest point — around 4am — the onset of that point can be delayed. The body is deceived into thinking the day is starting later. At present, most airlines dim the lighting to enforce the aircraft’s “night-time” period. “I’d prefer the lights to come on halfway through the night,” says Dr Idzikowski.

We land in Manhattan at 3pm (8pm London time). He suggests that my body clock will be reaching its slowest point at 4am, London time (11pm, New York time) and at that point, I should expose myself to bright light for three hours before shutting out all light completely. That means staying up until 6am. By 5.30 (10.30), I’m a little weary and cheat slightly — though Dr Idzikowski has assured me it is allowed — with two espressos. I walk along the Hudson River happily for an hour or so in the dusk, and it is not until 6.30pm (11.30pm), when I sit down on some stairs on Ninth Avenue that I feel it: not tiredness, for it is not yet midnight in London, but the sense of physiological incorrectness that is jet lag. At 9pm (2am), after a couple of drinks, I go in search of food, but the jet lag-avoidance regime has not factored in the problem of not having a reservation and it is only at 10.30pm (3.30am), having been turned away by several places, that I finally get a table. I sit down and the scene could not be brighter. I watch it all, dazed but defiant, and at 1am (6am), tumble into bed, managing to sleep through until 8 (1pm) — almost seven hours.

The next day I wake feeling relatively fresh, and need only a short rest in the afternoon to last through until my flight back to London. On board I have a light meal and fall asleep quickly, waking shortly before breakfast, slightly more than an hour outside Heathrow.

This approach could mean huge changes in airline practices. “I just have to prove this is workable,” says Dr Idzikowski. “Only then would the airline introduce it.”

The Deluxe Visor £250 www.outsidein.co.uk

What you can do to avoid it

Dr Chris Idzikowski, director, Edinburgh Sleep Centre, suggests:

Avoid eating just before the flight — the lower air pressure in the cabin can make the stomach and gut bloat, causing discomfort.

If you're going to be changing time zones, switch your clock over to the new one as soon as you board, and from that point, eat, drink and sleep according to your destination clock. (If you can, move to the new time zone a couple of days before travelling.)

Once on the plane walk around as often as you can. (Some airlines also have stretching exercises in their magazines.)

Eat light meals and restrict your alcohol intake to a couple of glasses of wine. Drink as much water as you can.

When sleeping, try to lie flat, or flatten out as much as possible. Use earplugs to reduce noise and wear an eye mask — even with eyelids shut you still have 80 per cent light penetration: the mask will reduce this to zero, which should trigger the secretion of the sleep facilitator melatonin.

If you have to work on arrival, have a nap when you get there. The conventional advice is not to do this, because it decreases sleep at night, but a nap increases mental performance. Most good sleepers can nap, and then sleep at night.

Melatonin can be purchased in the UK only with a prescription. In countries such as the US it is available over the counter; if you are going to use it, stick to low doses and if this doesn't work within 2-3 nights, abandon it.