Mankind has faced visual acuity disorders since its existence, but in the last hundred years this problem has been especially acute. Almost every third of us suffers from certain diseases of this kind. The representatives of the younger age group more often diagnosed, and in older people -. Both those and the second are faced with the need to use some kind of device for correcting visual acuity. It can be lenses or glasses. They need to be selected by a doctor, but there are some features that each user should take into account. Today we will talk about what glasses are best for vision.
How do progressive lenses work?
Progressive lenses can be used by anyone who needs extra reading power to avoid annoying distraction and eyeglass insertion depending on the distance they are looking at. Progressive lenses are three-zone lenses that are responsible for seeing objects clearly at different distances. The progressive lens highlights 4 areas with different properties.
Scope has given him a scope that provides comfortable distance vision, sits at the top of the lens and makes it easier to drive, watch movies in the cinema, or take in views while walking. The upper Dali area is chosen based on our natural behavior because most often we look straight ahead and to objects that are far away from us.
If you choose eyeglasses, remember that this is a personal item. You can not use the model that your spouse or anyone else is wearing, even if you think that it suits you. Lens curvature mismatch even by a quarter of a diopter can accelerate vision loss, in addition, it must be borne in mind that the center-to-center distance of the patient plays an important role in the manufacture of glasses. This is the interval between pupils, which may differ from different people and usually varies in the region of sixty-two to sixty-four centimeters.
The intermediate region is located in the central part of the lens and is otherwise known as the progression zone. The correction power in this zone increases from the correction values to the corresponding values. Ideal for viewing car dashboard or computer screen.
Proximity is located at the bottom of the lens and is responsible for reading or viewing objects close to the eye. The last area is called peripheral and is located on the sides of the lens - clear vision in this area is impossible. Lens manufacturers are currently in a race to offer customers a product with the smallest peripheral area.
Choice of lenses
You can purchase glasses with glass or plastic lenses. Experts say that each material has its own drawbacks and certain benefits.
Pros and cons of glass
So glass lenses are characterized by a high degree of durability due to their strength. When worn, even for a long time, they do not fade and block the penetration of ultraviolet rays. If special photochromic impurities are used in the manufacture of glasses, they can be used to protect against sun rays. You can also apply the most different coatings- polarizing, anti-reflection and anti-reflective.
Why use progressive glasses?
Progressive glasses provide a sense of comfort for those who have to wear two pairs of glasses every day. This is especially important for drivers who don't have to choose between looking at mirrors, dashboards or the road ahead while driving. Progressive glasses can drive comfortably and safely.
Progressive lenses and personalization
A common question and concern of customers who need progressive lenses is the issue of personalization. Nowadays, thanks to advances in optical technology, progressive lenses can be personalized just like any other. Only the surface of the mirror creates production problems, and not every manufacturer decides to do this.
However, such lenses have some drawbacks. Although resistant to scratches and other mechanical damage glass remains a rather brittle material and can break. In addition, from such a material it is difficult to manufacture lenses having a diopter of double curvature, which are necessary for people with astigmatism. In this case, it is better to use plastic options.
Early days with progressive glasses
The early days for people with new progressive lenses are cumbersome. Nearly half of patients first complain of headaches, headaches, dizziness, and nausea. Progressive lenses lead to small changes in behavior and habits. You need to adjust to using them to compensate for the disadvantages and maximize the benefits. After a month, 95% of progressive lens wearers are satisfied with the change, report no discomfort or discomfort, and find that the new glasses contribute to the comfort of their lives.
Glasses have a high degree of density, and this is noticeably reflected in their weight. Glasses with them often leave noticeable marks on the bridge of the nose, due to pressure from the frame.
When wearing lenses that contain photochromic impurities, there may be a delay in the perception of the surrounding world if a person abruptly enters a poorly lit room from a sunny street.
Authors: Alexander Grudzinsky, Magdalena Oleinichak, optician. Main consultation: Justina Moroz, optometrist, optician. Please don't be offended. Polish language pejoratively designated the term Dartonism of a person with all kinds of color blindness. And it was like this: Don McHerson - an American glass scientist and Frisbee fan - developed special glasses for surgeons. McPeerson accidentally discovered that the world seen by his invention looked very "candy".
The Don mute friend said he saw orange bumps he had never seen before. There are an estimated 300 million people with color vision impairments worldwide. One of the many forms of trichromatism is common, meaning it affects one in 12 men and much less frequently in one in 200 women. The California-based company that "brings color" to the world of color blindness is led by a team of researchers, engineers and technologists backed by an expert body of world-renowned vision researchers.
Pros and cons of polymer lenses
For the manufacture of such structures, special polycarbonate plastic is used. Its important advantage is its low weight, which is especially important for people with severe visual impairments. A plastic lens is less traumatic - it is almost impossible to break it before splinters appear. Also, the user can choose a variety of lens colors. As mentioned above, plastic options excellent for making complex diopter lenses with double curvature and designed to correct astigmatism. People with this diagnosis are prescribed complex prescriptions for glasses. Special lenses are made for them, having a cylinder and a sphere. Sometimes wearing such glasses causes discomfort - dizziness and pain, so the patient may take more than one year to find the right option for him.
The line was first created sunglasses. Pediatric glasses give puppies faster and more accurate interpretation of the appropriate color coding. In addition, lungs Sunglasses make life easier for athletes and those who need to protect their eyes while working. Through interactive entertainment illustrating the role that color plays in nature.
Visually impaired people can rent a pair of sunglasses to experience the event and enjoy it just like anyone who sees colors "normally". We also cooperate with other museums, - says Tony Dykes, for example, from the Museum contemporary art in Chicago. Special blinds sunglasses - sunscreen and indoor use for women, men and children can be bought and ordered, and without them.
Polymer lenses also have their drawbacks. The main one is the need for particularly careful use due to the high susceptibility to scratching. Glasses with such lenses fog up noticeably if you go into a warm room from a cold street, although now you can be offered special formulations, which are applied to lenses to prevent this problem.
Why are progressive glasses better than regular eyes? Typical single focus glasses provide clear vision at only one distance. In the case of presbyopia, people who clearly cannot see up close are required, by at least, two pairs of glasses: closer and closer, and often to indirect distance, watch TV or work on the computer. Progressive glass is a combination of all these glasses. One pair provides vision at all distances. The transition between zones to view at different distances is fluid and physiological, so progressive glass provides comfort in use, aesthetic appearance and does not require a constant change of points.
Plastic tends to accumulate a static charge, which is fraught with a strong attraction of dust.
Due to these factors, polymer lenses last an order of magnitude less than glass ones. In addition, they can break under the influence of low temperature.
Choosing a frame
When choosing a frame for your glasses, remember that the nose bridge is especially sensitive area, so you need to carefully evaluate not only your reflection in the mirror, but also physical comfort. Glasses should sit comfortably without pressing on the bridge of the nose, temples or behind the ears. Even minimal discomfort will increase over time and can provoke severe headaches.
How does progressive glass work? Progressive glass has a smooth power shift: from power to distance, through indirect distances to the nearest. Top part the glass has a far-sighted force and slowly sinks down through the zone to an intermediate distance. At the bottom of the glass is a near vision area that can be read. This is a natural reading position because each of us leaves our eyes.
Who is suitable for progressive glass? Progressive glasses are designed primarily for people with presbyopia, but young people and children with visual or binocular vision impairments also use progressive glasses. These glasses are suitable for almost everyone because they are built on the physiology of vision. Of course, there are competitions requiring close-up top of the glass, such as dentists, some professionals, librarians, electricians, plumbers or musicians, unfortunately typical progressive glass won't work.
Pay attention to the nose pads - it is better to give preference to silicone options - they can be adjusted to the shape of the bridge of the nose. The frame should not move off your nose when you tilt your head, nor should it twist on your face.
Important role the composition of the coating also plays, since some options, for example, nickel, can cause the development of allergic reactions. When choosing a frame material, it should be borne in mind that plastic, of course, is much cheaper than, for example, titanium, but it is much less durable.
However, these people may also use progressive glasses outside of work, for daily activities. It is always a good idea to explain to the optician exactly what your position and working and living conditions look like in order to offer you an optical solution that suits your visual needs.
Can't adapt to progressive glass? Many people say that it is difficult to get used to progressive glasses. Progressive glasses are built according to the physiology of the eye, so they do not require special education or time. However, these glasses are susceptible to errors such as abnormal distances and close misses, erroneously measured parameters required for the manufacture of eyepieces, and erroneous specifications. If no errors have been made at any of these steps and the optician has been informed of the visual needs of the patient, it is unlikely that a progressive lens will not be adapted to progressive glasses.
Conclusion
We talked about how to choose glasses for vision, which are better. Properly chosen glasses will help you not only see perfectly, but also add a certain zest to your appearance. Remember that trying to pick them up yourself can seriously harm your health, so be sure to consult a doctor.
Most people experience the full benefits of progressive glasses immediately after wearing glasses. Is it true that progressive glass has specific field vision? As in the case of the myth of adaptation problems, there is a myth with limited visual fields. Due to the gradual power shift, there are some slight image distortions at the periphery of the glass, but they are almost imperceptible. These fields are not excluded from the representation, they are perceived by the peripheral areas of the retina, which in themselves are not capable of perceiving details, such is their physiology.
It would seem that everything is simple, but in fact, pick up good points enough difficult task. What you need to know when buying glasses?
First steps
Before ordering glasses, you should check your eyesight with an ophthalmologist and get one, two or three prescriptions depending on the disease, occupation (driver, computer operator, dentist, accountant, etc.) or the purpose of wearing glasses . The same person, depending on the above indicators, may have different center-to-center distances and, accordingly, diopters.
Even in conventional monocular lenses, peripheral areas are distorted, not just progressive lenses. In the old structures, distortions of the periphery were actually perceived by some. However, modern designs, taking into account the parameters of the binding and the user, are designed in such a way that there is no distortion.
Is there a problem with image floating in progressive lenses? Reported difficulty going up the stairs? In older designs of progressive glasses, there was a certain amount of distortion at the periphery of the glass, which was the result of a smooth change in power at the center of the glass. When moving these distortions, they gave the impression of some image instability, which is called image float. This was especially noticeable on the stairs - the lines were not straight, only slightly curved. The latest progressive glass has almost completely eliminated this effect by adjusting it to the parameters of the luminaire and the user.
It is unacceptable to order glasses only based on the results of a computer examination without additional consultation with a doctor. It is also extremely harmful for the eyes to constantly wear ready-made glasses bought in a random place - temporary counters, in transitions and the subway, in the markets. When buying such glasses, attention is paid only to the appearance of the frame, the quality of the optics is not even discussed.
Immediately after the introduction of new progressive glasses, you can notice a light floating image, but very soon users stop noticing it. Stairs won't be a problem either, as the latest progressive glass is designed to keep straight lines straight.
What does it mean that progressive glass is personalized? Progressive glasses personalization refers to the advanced design of progressive glasses. Personalization is the development of progressive glasses, taking into account many parameters of the chosen holder and user. These are the distance and height of the pupils, the angle and curvature of the frame, the shape of the frame, the way the glasses are worn, the way the head is held, and even the way the head and eyes move. Measurements to create personalized progressive lenses are made with a special device.
The price of a mistake
What happens if the “wrong” glasses are bought, where the optical parameters (diopters and center distance) are not met, or the spectacle lenses are made of poor quality material? The process of addiction begins, in which the body tries to compensate for optical distortions (aberrations) at the cost of eye fatigue, headaches and further deterioration of vision.
These options allow you to create custom progressive lenses. It can be compared to a custom suit - this suit fits perfectly. The same happens with progressive personalized glasses - they fit the wearer perfectly and provide highest quality view without distorting or curling images.
What is the difference between expensive progressive glass and cheap? Cheap progressive glass are older structures that often have distortion in the image periphery. They are not personalized and may have lower quality anti-reflective coatings. Expensive glasses are latest achievements in the field of optical technologies that allow full personalization of lenses, provide a wide field of view and eliminate floating effects. Vision is dynamic and high-quality anti-reflective coatings protect the eyes from harmful radiation by eliminating glare, easy cleaning and high transparency.
Spectacle lenses
It is spectacle lenses that compensate for those refractive errors that are the cause of your poor vision. Therefore, choosing glasses, you must first choose the right lenses. So, what you need to know when choosing spectacle lenses:
Optical indicators (center-to-center distance, diopters)– this data should be given to you by the scoring specialist after complete examination your vision. Of course, glasses should be ordered only in specialized departments of pharmacies or opticians, where there is confidence that these indicators will be exactly observed.
Refractive index (index) of a spectacle lens- the most important indicator of the class of spectacle lenses. General rule- the higher the index, the smaller the thickness and curvature of the lens, giving the same diopters. And the stronger lenses you require, the more noticeable the difference. In practice, this means that lenses with a high index will be lighter, they will less distort your eyes and face, and it will be easier to fit thin and stylish frames to them. In modern lenses, the index fluctuates - for optical glass within 1.5 - 1.9, and for optical plastic - within 1.5 - 1.7. Lenses with an index close to 1.5 are considered low index, and those with an index greater than 1.6 are considered high index.
Spectacle lens material– currently the choice lies between glass and plastic. Definitely, the advantage cannot be given to either lens. Plastic, as a material, is much softer than glass and more vulnerable to damage. But all of today's high-quality plastic lenses come with a hard coating that makes them as scratch-resistant as glass lenses.
Benefits of plastic lenses- it's lightness - specific gravity optical plastic doubled less glass and therefore your glasses with plastic lenses will be much lighter. Less traumatic than glass ones, since plastic is more resistant to splitting and its fragments are less dangerous - therefore they are recommended for children, the elderly and drivers. Plastic provides great opportunities for processing, in particular for coloring lenses.
Benefits of glass lenses- In general, the refractive index (index) of glass lenses is higher than plastic ones. In addition, the strength (except impact) of glass is higher than that of plastic. This means that high-quality glass lenses, at equal diopters, can be thinner and flatter than plastic ones.
Anti-reflex coating is a special technology that greatly improves optical properties spectacle lens. Anti-reflex increases lens transparency by 8-10%. Due to the greater transparency and the absence of visual interference, anti-reflex lenses are more comfortable for the eyes and cause less fatigue when visual loads. IN dark time anti-reflex lenses allow you to see better while driving.
Thus, the choice of glasses should begin with the choice of spectacle lenses, especially if correction is required. high degree nearsightedness or farsightedness.
frame
Spectacle frames should adequately “frame” your high-quality spectacle lenses. What you need to know when choosing a frame for glasses:
Frames can cause allergic reactions. When choosing a frame, you should pay attention to the predisposition to allergies. Cheap metal frames of unknown origin can cause severe allergic reactions and skin irritation.
The frame must be comfortable- When choosing a frame, you need to pay attention to Special attention such details as the mobility of the nose pads - rigid nose pads often put pressure on the bridge of the nose and cause rapid fatigue. It is advisable to choose a frame with soft and movable (silicone) nose pads. The size of the temples must strictly correspond to the distance from the frame to the bulge behind the auricle. The temples should not put pressure on the temples and the area behind the ear. At big face it is desirable to select a frame with a springy hinge. The frame should be comfortable and not cause fatigue even with prolonged use.
The frame should be to your liking. The right frame is essential in creating the image and style of a person.
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