Myopia, means more than just needing glasses for distance. It is associated with a far higher than normal incidence of several eye diseases, including glaucoma, retinal detachment and disease of the macula.
Why do I have myopia?
Myopia, which is also known as short-sightedness or near-sightedness, is becoming more common. Opinion varies as to why the incidence has increased.
Some experts believe that in Australia it is simply because we have become more multicultural. As the proportion of Australians from East Asian descent increases, so too does the incidence of myopia (short-sightedness), which is more common in this population.
Another opinion seems to think that the extra reading, computer work, iPads and smartphones that we obsessively use has caused many people's eyes to become more myopic than they would have become purely from genetic inheritance.
What does it mean to have myopia?
The answer to this question really depends on what level of this eye condition you might have. Let's break it down:
VERY MILD MYOPIA
This can be defined from -0.25D to -1.50D. The best way to understand these numbers is that the lowest measurement of myopia is -0.25D, therefore the mild level is from 1 step of myopia to 6 steps.
This level of myopia is many cases can be a big advantage in today's society and work practice.
Assuming your eye muscles are coordinating properly, being slightly myopic means that your distance vision is not terrible and reading and computer work without glasses can be relatively stress free!
Mild Myopia can be defined roughly between -1.75D to -4.00D. Once you reach this level of myopia you normally are 100% dependent on glasses and or contact lenses, but you are not restricted in what glasses you can choose. Your spectacle lenses will be relatively thin and light. Eye disease is normally not significantly more prevalent than normal eye sight and laser eye surgery is a fairly simple procedure in most cases.
It is from here on that things start to change. Moderate myopia can be classified from -4.25D to -8.00D. In most cases without glasses or contact lenses you will be legally blind. The good news of course is that in most cases by wearing the correct glasses prescription or contact lens prescription your vision will be fully functional. This level of myopia is also important because -8.00D tends to be on the higher side of what can be corrected with laser eye surgery.
Certain eye diseases tend to become more prevalent when myopia becomes higher than -4.25D. In this group of myopia patients the following are more common:
- Retinal detachment
- Macula disease
Glaucoma has been discussed in some detail in previous posts. We will continue to update you with more information in the future. CLICK HERE for more information about glaucoma.
Retinal detachment is sometimes a medical emergency. It occurs with more frequency with myopia because the eye tends to be more "stretched" in myopia, so the back of the eye called the retina can tear and then detach. More information and a great video explanation can be found by CLICKING HERE.
The picture on the left is indicative of glaucoma. The picture on the right is what will be seen when the retina is detached.
Once myopia is greater than -8.00D it can be classified as high. The risk of retinal detachment is higher, as is glaucoma and macula disease. At this level the retina needs to be carefully observed on every visit, even with no symptoms. Digital photography is not enough. Eye drops need to be used that open up the pupil of the eye, so that the peripheral retina can be viewed in detail using an instrument called a binocular indirect ophthalmoscope in conjunction with a condensing lens. Using this specialised piece of equipment our optometrists at the Eye Practice are able to give you a complete and comprehensive retinal check. Retinal imaging will record the baseline state of your retina for comparison to future images. OCT (Optical Coherence Tomography) will also be used to see what's going under the surface of the retina, particularly around the critical central part - the macula.
Finding subtle irregularities in the retina and macula using this type of specialised equipment can discover the beginnings of retinal detachment and macula disease before they become bigger problems.
Glasses for high myopia
Making glasses or contact lenses for these types of prescriptions is where The Eye Practice excels. Choice in frames and spectacle lenses becomes critical in making them functional but also cosmetically appealing. Typically people that are greater than -8.00D of myopia prefer contact lenses as the vision is better and more natural. Maximising contact lens success is another of The Eye Practice's specialities. We understand the importance of contact lenses in this vision category. We therefore will pay a significant amount of attention in guiding our patients to current and future success.
Worried about your eyes? For a discussion around myopia control and advice around how often to have your eyes examined for eye disease, call us on (02) 9290 1899 or