MYOPIA – NEARSIGHTEDNESS

Myopia (nearsightedness) is a refractive disorder where distant object cannot be seen clearly. This condition occurs because light rays coming to an eye from distant object focus in front of retina.

The most common reason for myopia is because eyeball becomes elongated and normal refractive power is now too strong for an eye. The images formed on the retina are blurry and therefore cannot be seen clearly. This form of myopia is known as axial myopia.

In some rare cases it is possible that refractive power of an eye is too strong for a normal size of an eyeball and images from distant objects again focus in front of retina instead on it. The reason is either a strong refractive power of cornea (for example in condition known as keratoconus), or lens (for example condition known as lenticonus).

Can accommodation compensate strong refractive power?

Unfortunately no. Unlike some forms of hypermetropia accommodation cannot correct myopia. The reason is because the accommodation works by increasing refractive power of lens. It cannot weaken it over a certain point. When cilliary muscle is fully relaxed (like when we focus on distant objects), refractive power of the lens is maximally reduced. In myopia maximally reduced refractive power is still too strong.

Myopia mostly occurs in school children, although it is not impossible that it occurs very early in childhood. It rarely occurs in the adulthood. Development of myopia in adulthood, especially after 40 years of age, may be the first sign of cataract.

The main cause of myopia is unknown. Some studies show that it has genetic origin since it is more common in some families. For benign myopia it shows autosomal recessive heritage. Malign myopia is more likely to be inherited.

Some studies show the relationship between eye strain in intensive close work and development of myopia. Most people that spend a lot of time in front of computer screen, or in front of the book develop myopia at some point of their life.

Also more and more people become nearsighted which also could indicate that the stressful way of life and bad nutrition can also be responsible. Myopia was very rare condition in the past.

During adolescence period when our entire body grows, eyes also grow and that is one reason that results in increasing of myopia.

Increased eye strain with too much close up work may lead to development of myopia. Some scientists believe that myopia occurs as some form of “long term” accommodation for close work. When we spend too much time looking at close objects, cilliary muscles are constantly tense. The need of cilliary relaxation may lead somehow over time to elongation of an eyeball, so that the close up work could be done with reduced accommodation and reduced contraction of cilliary muscle.

People that suffer from myopia, especially without corrective glasses or contact lenses, strain to see distant objects. This strain may lead to the development of myopia.

However, eye strain is scientifically more considered to be a contributing factor in the development of myopia, than its cause. There are also some other factors that may be the reason of eyeball elongation, like dopamine deficiency, form deprivation and optical defocus.

The main difference is the pathologic changes on the eye fundus. Benign myopia usually starts in school, develops during adolescence period and stabilizes in the adulthood. It rarely grows beyond -7.0 D and it never has any pathologic changes on the eye fundus.

Malign myopia usually starts in early childhood and is very progressive condition. It doesn’t show any tendency to stabilize over time and often grows beyond -10.0 D. Sometimes it can reach -15.0 D or even -20.0 D. Unlike benign myopia there are always pathologic changes on eye fundus. This myopia is very difficult to correct and it often requires surgery (scleroplasty) to stop further progression.

The best way to know is to visit ophthalmologist and take eye exam. If you are having difficulty seeing distant objects, reading small signs in the distance or recognizing other people, that could indicate that you suffer from myopia. Most people though don’t have any difficulties and they think they see perfectly until they take eye exam.

This term is used to describe a condition usually after a longer period of intense close work and accommodation. It is also known as pseudomyopia. The cilliary muscles become exhausted and unable to fully relax. The refractive power of an eye becomes temporary stronger and distant objects can’t be seen clearly. This condition is completely reversible after a period of rest when cilliary muscles relax.

The condition may last for a few days. When a person with temporal myopia goes to eye exam, it will show the presence of myopia and it may be misdiagnosed as real myopia. That is why diagnose of myopia must be verified with pupil dilatation and cilliary paralysis (eye drops with some form of atropine derivate are administered). Paralysis of cilliary muscle is essential and will cure temporal myopia.

Unfortunately myopia has a tendency to grow. It can’t really be predicted how much it will grow, but for many people growth stops in adulthood. Wearing corrective eyeglasses and contact lenses little does to stop further progression.

The main options for myopia treatment are corrective eyeglasses, contact lenses, refractive surgery and orthokeratology. Eyeglasses and contact lenses are temporary solutions, while refractive surgery and orthokeratology permanently reduce myopia.

There is also an alternative method consisting of eye exercises and eye relaxation techniques. It was first introduced by ophthalmologist dr William Bates, but due to the inconsistency of his work and some potentially dangerous methods it was rejected by the mainstream of medicine. His original techniques were adopted and modified so that they pose no danger anymore and now exist as alternative method of myopia treatment.

I am not aware of any scientific study that proves that these methods work or not, but that doesn’t change the fact that many people claim that they have been helped by these exercises. In my professional opinion, it can’t hurt to try. Read more about eye exercises here.