Understanding Refractive Errors

in StemSocial2 months ago
Greetings to all and sundry,

It's been quite a while since i got back on hive and so having had this opportunity today and having finally graduated as a licensed Optometrist from KNUST, Ghana, i wanted to get back and share with you as i was doing in the past.


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And so for today let's begin with the most common cause of visual impairment across the globe which is easily treatable yet many can't afford in many developing countires, Refractive Errors.


Introduction

Refractive errors are basically state or conditions of the eye where light emanating from far thus 6meters or more end up not focusing at the point they ought to within the eye.

What happens is that the eye just like using a magnifier to small prints or as the young adventurous kids would like to do, focus sun on to a paper or polythene to burn, the eye also focuses light from things around into the eye.

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This light passing through the various media of the eye has to come to a stop at a point called the retina, when this is done well in the ideal conditions with all things been equal then the individual gets to see things lucid as it is. Anything other than this results in refractive error.

Refractive errors comes in three folds, we have myopia or shortsightedness, hyperopia or farsightedness and astigmatism however for the purpose of today's lesson we will look at only myopia whiles we treat the others in the coming days.


Myopia

Myopia comes about when this light from a distant object as already discussed above do not fall on this area in the eye called retina where it ought to be rather it falls in front of it.

This results in blurred images been sent to the brain for processing and the individual would thus have difficulty seeing at far. These individuals known as myopes tend to suffer a lot in class and may have to be quite close to the board to see.

The name near sighted came as a result of the fact that whiles they can't see well from far their vision at close range is extra powerful and super sharp and this tends to be a bonus for them as they grow older and presbyopia sets in however that's another discussion for another time.

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So why is the image forming in front of the retina? Two theories surround that and the first is that the eye's refractive state is more powerful or higher than the equivalent length or distance of the eye, hence the focal power do not correlate. The second theory as you may have guessed by now is that the eye ball is longer than expected.

Myopia is nothing to be shy or scared off, it happens all the time and although it is becoming a global concern now with more research in vision science focusing there, the good news is that it can easily be correct with a simple lens, glasses or contact lens.

Myopia may not give any other symptoms aside the blurriness you may experience however if and when not managed especially in infancy we may have what we call lazy eyes or amblyopia develop later on.


Treatment or Management

Here is where it get's a bit tricky. Now what you need to understand as a myope or a patient is that your glasses is an optical device and thus correct your error so long as you wear it.

It is not a drug and so your eye is not going to get better as the year progresses for you to take of your lens. Many patients do not like to here this however it is the truth and it is better to see better with your lens than not.

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In a latter time we will discuss the myths surrounding spectacle wear. There are also other management options aside glasses some of which include surgery, lasik, contact lens and orthokeratology.

Many options are coming out day in day out as a results of research and i would advise you talk with your optometrist about your options.


Conclusion

It is an absolute pleasure to have found my way back to the science community of the blockchain and it is a pleasure indeed to be here. Thanks for reading and thanks to everyone for having me and greetings to prof @lemouth and @gentleshaid. Love from Ghana.


For extra reading

Bremond-Gignac D. Myopie de l’enfant [Myopia in children]. Med Sci (Paris). 2020 Aug-Sep;36(8-9):763-768. French. doi: 10.1051/medsci/2020131. Epub 2020 Aug 21. PMID: 32821053.

Cho P, Tan Q. Myopia and orthokeratology for myopia control. Clin Exp Optom. 2019 Jul;102(4):364-377. doi: 10.1111/cxo.12839. Epub 2018 Oct 31. PMID: 30380591.

Harb EN, Wildsoet CF. Origins of Refractive Errors: Environmental and Genetic Factors. Annu Rev Vis Sci. 2019 Sep 15;5:47-72. doi: 10.1146/annurev-vision-091718-015027. PMID: 31525141.

Naidoo KS, Jaggernath J. Uncorrected refractive errors. Indian J Ophthalmol. 2012 Sep-Oct;60(5):432-7. doi: 10.4103/0301-4738.100543. PMID: 22944755; PMCID: PMC3491271.

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