Hello everyone I am “El Óptico de youtube” and today I bring a video that belongs to the series of refraction defaults In this video we are going to talk about myopia Would you like to know all its characteristics? Stay with me and you´ll see. LET´S GO INTRO Myopia is, by definition, a refraction default on the eye in which… ok, you can look up for this by yourself, can´t you? What I can tell is that a myope eye focuses distant objects ahead of the retina Here comes the first important tip A myope person can´t do more than using glasses, contact lenses or use surgery to see well. His eye doesn’t have any possibility to focus distant objects. Why does this happen? This can happen because of several reasons. The first reason it´s because the eye may be way too big, therefore the focus falls ahead of the retina. The second reason is because the cornea and the lens can be too powerful and the image also falls ahead of the retina. Another reason why we can be myope it´s because the refraction index of our transparent media are bigger than usual. This can also cause distant objects to form images ahead of the retina. There are different types of myopia: degenerative, congenital (normally associated with eye diseases and also what is called plain myopia, that is what I have and it is not associated with any disease and it is also the most common type. It normally appears around the age of five and it is progressive until the person reaches adult age and the eye has completely developed itself. To correct myopia we have glasses, contact lenses (we will talk about these ones in other videos) and it also exists eye surgery. It can be divided into lasik surgery and surgery by implantation of an intraocular lens. Here you have the second tip, and it is about orthokeratology. You may never have heard about it before. It is a technique by which we sleep with our contact lenses on. These are rigid lenses that modify the curvature of our cornea to make it flatter. That eliminated dioptrias of our cornea and allows us in the morning, when we remove the contact lenses, to see wonderfully. What should we consider if we are myope people and we are about to get our first pair of glasses? It´s simple. The lenses for myope people are divergent. That means they are flatter at the centre than in the periphery. This means that the bigger the glasses frame is, the heavier it will get and the thicker it is going to be at the periphery. So, the third tip we have to know is that it is always better to get smaller frames and like this our glasses will be lighter and cheaper. What should we consider when talking about contact lenses? Not much, and I will talk about lenses in other videos. Basically, there are different types of lenses, ones more expensive than other. Something I can assure is that the white brand lenses of shops are good lenses, more if they are made of silicone hydrogel. An extra tip i´m going to give you is about fake myopia. When fake myopia takes place there is not a real myopia, but other processes that may look similar to myopia. We can think we can´t see properly from a distance and think we have myopia when, on the contrary, another process is happening. There are three: nocturnal myopia, accommodative spasm and instrumental myopia. Nocturnal myopia is the blur that happens under conditions of low visibility. It is not necessary to be under the nightlight, but mainly when we are in gloom, the pupil gets bigger and generated a blur that is similar to the blur that myopia produces. This explains why people with myopia also suffer from nocturnal myopia. The accommodative spasm happens when we spend a lot of time working from a close distance and we force our lens to be constantly accommodated to see close objects. It can happen either working, studying or reading. We block the lens in a way that the moment we try to look away the lens seems to be seized. Instrumental myopia happens when we spend a lot of time working with devices, such us microscopes, which produce a blur. This is not myopia but it gives us the impression that objects are closer than they truly are creating a fake blur. As I want my videos to be short I am going to carry on uploading videos and explaining all this stuff. I will make separate videos about orthokeratology, for example. Or explaining more about nocturnal myopia or instrumental myopia. My intention is to make short videos, easy to understand where you can add your comments and I will answer them back little by little. Like this, we can create an interactive community so please, subscribe and if you liked the video share it in your social media. I hope to see you in my next video about hypermetropia that you can find in my channel really soon. I hope to see you next week. Bye!