A Question of Health: Why don't I sleep well in the Alps? And can I rinse my contact lenses in tap water?

I know I am not alone in suffering high alpine insomnia and I am curious as to its cause. Whenever I am at a high altitude in the Alps, I sleep badly and not for long. It's not such a bad affliction, as I get to watch the sun come up over the Alps while reading. I am not tired during the day, so I am obviously not losing sleep I require. However, I am curious as to why a person who requires seven-and-a-half to eight hours sleep at sea level in London can get by with only five hours sleep in Verbier in the Swiss Alps. My health is normally very good, but I now, at 60, have to take drugs for hypertension from which my mother and grandmother both suffered. Might that have something to do with it? I have a friend who won't go to the Alps as she can't sleep, so I know this is not uncommon.

SLEEPLESS IN VERBIER

I know I am not alone in suffering high alpine insomnia and I am curious as to its cause. Whenever I am at a high altitude in the Alps, I sleep badly and not for long. It's not such a bad affliction, as I get to watch the sun come up over the Alps while reading. I am not tired during the day, so I am obviously not losing sleep I require. However, I am curious as to why a person who requires seven-and-a-half to eight hours sleep at sea level in London can get by with only five hours sleep in Verbier in the Swiss Alps. My health is normally very good, but I now, at 60, have to take drugs for hypertension from which my mother and grandmother both suffered. Might that have something to do with it? I have a friend who won't go to the Alps as she can't sleep, so I know this is not uncommon.

The insomnia that some people suffer at high altitudes is a minor manifestation of a condition that is known as high altitude illness. Another name for this condition is acute mountain sickness. At altitudes between 1,850 and 2,750 metres, 22 per cent of people develop some symptoms of the condition known as high altitude illness. Above 3,000 metres, 42 per cent of people suffer symptoms. You are more likely to develop symptoms if you go straight to high altitude from sea level.

If you ascend slowly, your body acclimatises and is less likely to be disturbed by the altitude. The severity of high altitude illness symptoms also depends on the altitude that you sleep at. The village of Verbier is 1,500 metres above sea level and the summit of Verbier is 3,300 metres high. I don't suppose that you sleep at the summit, but you may find that if you choose accommodation that is at a slightly lower altitude next year, the insomnia will be better.

Another suggestion is to book a longer holiday in the Alps next year. Most of the symptoms of high altitude illness usually improve with time. Your sleep may improve after you've been in the mountains for about five days. Finally, avoid alcohol. This is bound to make your symptoms worse.

EYE TO EYE CONTACT

I have worn hard and gas-permeable contact lenses for more than 25 years, since the age of 20, and only once suffered an attack of conjunctivitis or any other eye infection. During my most recent annual check, the contact-lens practitioner scolded me for rinsing my lenses in tap water after cleaning but before storage in sterile soaking/wetting solution. She alleged that tap water contains dangerous bacteria that may cause an eye infection and "even blindness". I was put under strict instructions only to use saline solutions out of a spray or bottle to rinse the lenses.

My reaction to this was: this is a scare tactic to get you buying even more over-priced lotions and potions. If London tap water were that dangerous to the eyes, surely there would be a general heath advisory not to splash water in your eyes if they feel tired? I have always been scrupulous in my daily cleaning regime as to thorough cleansing and overnight soaking in sterile solution, but I take the risk of an infection from London tap water in this context to be negligible. Am I right or deluding myself?

Your contact-lens practitioner is talking about a rare type of eye infection called acanthamoeba keratitis, which is caused by an organism called acanthamoeba. Acanthamoeba are not bacteria, they are organisms called amoebae. They live in soil and water, and they are quite difficult to kill by ordinary disinfection methods. The chlorination of drinking water, for example, may not kill these organisms. Tap water, particularly in areas with a lot of limescale such as London, may contain acanthamoeba.

If they come into contact with lenses, particularly soft lenses, there is a risk of introducing infection into the eye. The risk seems to be greatest if you wear your lenses for extended periods. The most conservative advice would be never to let tap water come into contact with your lenses. As you have proved to yourself, however, the risk of getting an infection with acanthamoeba is incredibly small. Simply splashing tap water into your eyes is less risky than putting a lens in. If the lens has acanthamoeba stuck to it, it is much more likely to cause a serious infection.

HAVE YOUR SAY

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Keeping a migraine diary is a great diagnostic tool - mine showed migraines just before my period. Now I stick on an Evorel 50 HRT patch just as I feel pre-menstrual (I don't use HRT at any other time). I peel it off after my period and have had 100 per cent success. It was the sudden hormone dip that triggered the migraine. Rizatriptan is a fast cure, too.

Some straight talking about laser eye surgery from JRG:

I also asked my optician about surgery. He said I was an ideal candidate because my level of sight defect was in the middle range. I would notice a significant improvement whereas people with a slight defect often notice little change. He said I would still need spectacles for reading. He also said that most people experience dryness following surgery. I already have a problem with this and use drops on a regular basis. I suggested perhaps it was not such a good idea then and at this point he agreed. I felt I was getting sensible advice.

Please send your questions and suggestions to A Question of Health, 'The Independent', Independent House, 191 Marsh Wall, London E14 9RS; fax 020-7005 2182; or e-mail to health@independent.co.uk. Dr Kavalier regrets that he is unable to respond personally to questions