-== N. F. Burnett Hodd ==-

Advice to parents
From Nigel Burnett hodd

There are several ways to correct short sight other than with spectacles. These are by changing the front of the cornea to be flatter or changing the way people see things by thought and exercises.

First of all people should use their eyes in a way that does not encourage their eyes to go myopic in the first place. Ask yourself the question – why do short sighted people have short sighted children. Answer – because they all behave in short sighted ways! The other answer is – because it is hereditary. There are some general rules for parents to discourage their children from going myopic:

Do not have patterned cot sheets and do not hang mobiles etc only inches from the baby’s eyes! A baby will naturally focus very close looking for milk. The effect of focusing puts pressure on the muscles in the eye that pull on the walls of the eye and encourage the eye to grow larger. Large eyes are short sighted. Small eyes are long sighted. The occasional close focus is fine but once the baby is attached to the breast it should look further away or shut its eyes. If a baby can look constantly close too at patterns this may encourage their eyes to go myopic. Hang mobiles at least 50cms from the baby and don’t have patterns to look at close too.
When a child is learning to read ensure all reading material is kept at least 30cms from the eyes. A page at 30cms needs 3 diopters of accommodation to focus but a page at 10cms needs 10 diopters. That is 3x as much focusing to read. Over a period of time and habitual use this causes the eye to go myopic.
Whilst all parents want their children to be clever academically it is important to do lots of distance activities such as walking, cycling, sports. If a child is permanently focusing close too then the eyes will tend to be myopic.
Once a child becomes myopic or if it is believed that excessive reading is taking place then muscle relaxing reading spectacles can be given or bifocal spectacles. Once again it relaxes the harmful effects of over focusing.
Exercises can be given to help muscle control if a child can’t turn their eyes in properly. Convergency Insufficiency is quite common and if the muscles don’t turn the eyes in properly there is a tendency to over focus.
A study in the United States found that where children had a night light in the bedroom during the early years there was a greater proportion of myopia when they grew up. So – it seems that leaving a baby in light allows the eyes to focus too close too whilst the child is asleep. It seems it is better to be totally in the dark and then the eyes rest better when the lids are shut. However – if a child is afraid of the dark we don’t recommend that you force them to be in the dark against their will. Better to be myopic than disturbed!

Use of Contact Lenses At All Ages

Once myopia starts it is often difficult to stop it progressing. However one treatment is to fit Hard / Rigid contact lenses. Research suggests that the use of rigid lenses inhibits the growth of the eye and halts the myopic creep. So children who are myopic (as young as 3 - 4) can be fitted with hard lenses to hold things back. However – usually the myopia does not start until the beginning of puberty.

Some contact lenses can be fitted in such a way as to reduce the myopia. This technique is called Orthokeratology. Special Reverse Geometry rigid lenses reshape the cornea and reduce the myopia. When the lenses are removed the patient sees without glasses. This is especially useful in some occupations (e.g. – sportsman, policeman).

Soft lenses do not halt myopia.

Use of Refractive Surgery for Over 21’s

It is possible to surgically alter the shape of the front of the eye to make it less curved. This reduces the myopia. It is also possible to surgically insert within the eye a contact lens like disc to change the prescription of the eye. It should be realised that using surgical techniques does not cure myopia it is merely a way of reducing the need for corrective glasses. So people who have surgery will still have myopic children unless they change their ways as detailed above. There are several types of surgery in common use today and they are called:

R.K. Radial Keratotomy Here cuts are made around the cornea in a radial fashion and when the cornea heals it adopts a flatter shape. Known as "Slash for Cash" in the profession this technique has been superseded by Laser Surgery

P.R.K Photo Refractive Keratectemy is the technique where the surgeon peels off the skin on the cornea and uses a laser to burn away the central surface of the cornea to flatten the shape. The tissue removed is gone forever. It takes a few weeks for the eye to heal up and some pain is evident. Eventually, in about 90% of cases people can see well enough without glasses or contact lenses. This technique is now being superseded by LASIK

LASIK Laser in Situ Keratomyleusis is also known as "Flap & Zap". Essentially a section of the cornea is cut and flapped back. The laser is used to burn away the central cornea and then the flap is sealed back down again. The advantage of this technique is that higher prescriptions can be done and there is less damage to the eye. Success rates of 98% are being reported.

As an optometrist I dislike any techniques that leave an eye damaged or more susceptible to problems in the future. So I do not recommend surgical intervention just to have thinner glasses. However – people can be strongly motivated to do away with spectacles and contact lenses are the best reversible option. If contact lenses fail then surgery may be a good option for some people as long as they understand the risks.