Do you see badly up close and wonder if you have presbyopia or tired eyesight? Do you want to know what it’s called when you don’t see up close? You have to be attentive throughout the post.
Here you will find everything you need to know about your problems in order to see well up close.
- You will know why you see badly up close
- You will know if you need glasses and what kind
- You’re going to discover the phenomenon of vision.
- You will know if you should go to an eye care professional.
Definition of presbyopia or eyestrain
It is a visual defect that prevents correct near vision. It is associated with age, since it usually appears around the age of 45. Its cause is the deterioration of the ocular structures responsible for focusing up close (technically called accommodation). It is progressive but does not pose any risk to eye health. It can be solved with glasses, contact lenses or surgery.
If you wanted to know what’s wrong with you because you can’t see badly up close, this is enough. If you want to know everything and take advantage of a special offer, read on.
The first figure illustrates the internal anatomy of the eye, which is important for knowing what tired eyesight consists of.
The two key parts of the eye related to presbyopia are the ciliary muscle or body, the crystalline lens and also the fibers that support this crystalline lens, which are attached and controlled by that body or ciliary muscle.
The second image portrays the equation of the human eye to a camera. They are two optical systems with many similarities and will also help us to better understand what we are going to explain next.
But that’s not all.
First, take a look at these two animations, which illustrate the phenomena of vision and accommodation.
How is human vision produced?
The phenomenon of vision is explained as the ability of the brain to interpret the images that form in the retina of the eye.
Yes, in the retina.
These images penetrate the eyeball through the cornea, pass through the crystalline lens and reach the retina.
We start from the assumption that the eye has almost no visual defect (i.e. myopia, hyperopia or astigmatism).
In this case, if the eye looks from afar, the phenomenon of accommodation does not take place, which you can see illustrated in the upper animated image, that of the tree.
When the eye focuses on the tree, the lens will not work.
If the eye focuses on close objects (A in the figure), the accommodation system is unconsciously activated, the ciliary muscle begins to work and by means of the fibers that join it to the crystalline, they make it begin to change curvature and in this way the eye is able to focus on objects located in a close environment.
Origin of eyestrain
The origin of this visual or refractive defect is not clear.
Most scientific texts allude to the loss of elasticity of the crystalline lens to change its curvature.
Others speak of the loss of functionality of the ciliary muscle to make the crystalline work.
I believe that the most adequate description is due to a sum of the two: loss of elasticity of the crystalline and loss in the tone (strength) of the ciliary muscle.
When presbyopia begins, the ciliary muscle is not able to make the fibers that bind it to the lens work.
This crystalline lens itself will already have a loss of elasticity, so it will not be able to properly modify its curvature and it will not be possible to focus on nearby objects.
Symptoms of Presbyopia
The symptoms of tired eyesight are easy to recognize: we begin to see blurry near but moving away the object we want to see, the sharpness is greater, right?
But be careful,
Since it is a visual defect that advances with age, there will come a time when we cannot read holding the book, newspaper, mobile, etc; with our hands since we do not have
Other symptoms such as visual fatigue, headache, itchy eyes, or abnormal drowsiness may also appear.
The easiest way to correct this visual defect is with close-up glasses.
But it’s not all there.
If a person already wears glasses for distant vision, they should use a different prescription for near vision. That prescription is known as Addition. I repeat: ADDITION, not addiction.
There are different lenses/glasses to correct it:
Monofocal lenses, progressive lenses, bifocal lenses, trifocal lenses, etc.
The progressive glasses that we will talk about in successive articles, is the best option to correct an incipient presbyopia. In other words, that of a person who has just realised that he is not seeing well up close.
There are several types of progressive glasses, and if you follow the links in the article or blog, you will be able to know exhaustively all their characteristics, advantages, disadvantages, prices, etc.
Glasses with bifocal lenses are in disuse due to their lack of functionality.
They are the typical glasses with the small window at the bottom that many older people wear. It was a very widespread and quite acceptable option about 40-years ago.
Another way to correct presbyopia and largely unknown to the general public is multifocal contact lenses, better known as progressive contact lenses.
These lenses are not a definitive solution because optimal visual acuity results are not achieved for all distances, but they are a great way to get rid of glasses a few days a week, or a few hours a day.
Above all they are related to moments of leisure.
Finally you have to know that there is surgery.
The presbyopia operation is currently possible and the results can be good.
There are several ways to correct presbyopia by surgery, but basically they are divided into the use of the laser, and the replacement of the lens with an artificial lens. It usually gives satisfactory results.
In successive articles we will explain in a more concrete and developed way the different techniques of correction of presbyopia or tired sight.
Although presbyopia is a progressive visual defect, it poses no risk to visual health, you are not going blind or anything like that.
It is a manifest discomfort for people who need to see close up continuously.
Or simply and as we mentioned at the beginning of the article, for anyone who wants to see the time on the clock, send a message on their mobile, or read the newspaper.