Daily toric lenses - principles of selection and use

General information about daily disposable contact lenses for eyes

This type of lens has a number of advantages that are difficult to keep silent about and which stand out against the background of other advantages of other optical products. Firstly, they allow you to minimize the time of getting used to a foreign object in the eye, since, most often, they are developed from extremely thin material. Plus, they perfectly allow air and oxygen to pass through, which, in turn, negates the occurrence of such an unpleasant phenomenon as hypoxia. Since replacement should be done every day, disposing of old lenses in the evening and putting on a new pair in the morning, the products do not require maintenance. On the one hand, this saves time that you could spend on cleansing, and on the other hand, it guarantees safety and sterility. There are no protein or lipid deposits on daily lenses, and bacteria do not multiply. These lenses are especially good for sensitive eyes, as well as for people prone to allergic reactions. Of course, these lenses cost a little more than bi-weekly or monthly optical products, but if you look differently, there is a chance to save on cleaning products and accessories. Below we will talk in more detail about the characteristics of such lenses and what parameters you should pay attention to when you select them.

Preparation for implantation

Preparation for the intervention consists of undergoing a complete examination of the patient. Typically the examination includes:

• Assessment of psychological state.
• Assessment of general health.
• Assessment of the accommodative abilities of the optical system.
• Determination of individual parameters of the cornea of ​​the eye.
• Determination of the state of the visual fields and retina.

Before surgery, a binocular vision test is performed. Contrast sensitivity and quality of stereoscopic vision are assessed.

Before implantation, the patient is usually asked to “wear” multifocal contact lenses in a test mode.

What are the characteristics of daily disposable lenses?

So, what should you pay attention to when choosing daily contact lenses? First, check with the manufacturer. Today, the ophthalmology market is extremely diverse, in this regard, you may give preference to a little-known brand that may not produce the highest quality or safest products. Accordingly, their price will be lower. There are a number of companies with an excellent reputation that have managed to establish themselves: they produce good products that are developed on innovative equipment using high-quality materials and advanced technologies. Below, in our article, we will give examples of the most popular brands and their best ephemera products.

The next point that is extremely important for any type of lens is oxygen permeability. Why is this characteristic so important? The thing is that the health of your eyes and the comfortable wearing of lenses will depend on this parameter. Another key point is moisture content. In terms of its significance, it is equal to the previous one. The higher the level of hydration in the contact lens, the more convenient it will be to use, and the eyes will not experience a burning sensation and a feeling of dryness. In order to produce such daily contact lenses, the manufacturer uses special moisturizing components.

Material. What the lenses are made from is very important: it determines whether they will be hard or soft. Hard lenses were one of the first, and today leading manufacturers most often make only soft daily lenses. Traditionally, hydrogel or silicone hydrogel is used. The latter material is considered more popular.

Stiffness or elasticity. Another key parameter for contact products, which will determine how well the lens follows the shape of the surface of the eye.

Allergy. It is very important that the wearer does not have any allergic reactions to the material from which the contact lenses are made. This doesn’t happen often: manufacturers have learned to make products that are as hypoallergenic as possible. By the way, hydrogel daily lenses contain more water and are less allergenic.

IOL manufacturers and popular models

Regardless of who creates the implants, they have a number of requirements:

• Maximum visual visibility,
• Possibility of installation through a minimal incision,
• No risk of secondary cataracts.

Products from the following manufacturers meet all these requirements:

• Alcon. The company mainly produces hydrophobic models with minimal thickness,
• Rumex International. The products make it possible to achieve uniform stretching of the capsular bag during implant insertion,
• AcrySof ReSTOR. The brand's products are famous for their minimal lens thickness, which allows them to be inserted through a microscopic incision,
• AcrySof IQ. Models are equipped with a protective filter against the blue spectrum, this reduces the risk of developing age-related macular degeneration.

The most popular IOL models:

• Acrosof ReSTOR Alcon. Provides visual acuity at close, medium and long distances, regardless of the degree of lighting,
• AcrySof IQ Natural Alcon. This product has the only drawback: light streams pass through its surface at different distances, causing spherical aberrations,
• AcrySof IQ Toric Alcon. A toric lens can effectively combat astigmatism,
• Akreos AO MI 60 Bausch&Lomb. The product is made of hydrophilic acrylic (composed of 26% water). The implant is installed through a microscopic incision,
• AT LISA TRI 839 MP Carl ZEISS. Distributes light fluxes at different distances, thanks to which the patient can see well at close, medium and long distances,
• Hydro – Sense Aspheric. Anti-glare technology was used to create these lenses, so the risk of visual distortion is eliminated. The unique shape of the model takes into account all the anatomical and refractive nuances of the eye.

What types of daily contact lenses are there?

Dividing daily contact lenses into subgroups, oculists distinguish: silicone hydrogel, hydrogel, toric and colored hydrogel and cylindrical. Let's talk about each type in more detail.

Silicone hydrogel daily lenses are preferred by most consumers. The rating of the most popular optical products of this type includes lenses 1-Day Acuvue TruEye, ClearLux OneDay Aspheric, Maxima 1-Day Premium. The best one-day lenses from the first company, since the totality of their characteristics allows them to stand out from the rest of the three. The average oxygen permeability of optical products of this brand is 33%, which is a high figure that allows you to even sleep in such contact lenses. But this is not recommended - there are special optical products for such purposes.

Which hydrogel lenses should you choose? Experts recommend paying attention to such products as Biotrue ONEday, 1-Day Acuvue Moist, SofLens daily disposable. Number one on this list will be Biotrue ONEday. These contact lenses are good and are more in demand, since their oxygen permeability is more than 50%.

Colored hydrogel contact lenses. Of course, initially this type of contact product was used exclusively for cosmetic purposes, but today many manufacturers are developing models that can not only change eye color, but also correct vision or hide any imperfections. By the way, such lenses may also be suitable for sensitive eyes.

Daily toric lenses, in turn, are distinguished by the fact that they do not cause side effects even for those who have just started wearing lenses without having any previous experience. They perfectly follow the shape of the eyeball, are almost not felt when worn throughout the day and maintain clarity of vision. This type of lens, such as cylindrical, is characterized by a long period of adaptation. They are prescribed for astigmatism, that is, for deformation of either the cornea or the lens.

The best one-day contact lenses among this type of model are the following: 1-Day Acuvue Moist, Clariti 1 day toric. Let's look at each one separately. The first are the most famous and, perhaps, the best contact lenses for sensitive eyes, the second are more advanced and are made of silicone hydrogel.

Multifocal IOL. What is this?

An IOL is a lens that refracts light rays, which helps form an image on the retina. Such an optical mechanism has two elements - support and optical. The first one serves for reliable and strong fixation of the artificial lens. The optical element has a special diffraction zone, which allows the eye to receive the most correct picture. A multifocal intraocular lens includes several foci simultaneously. Each focusing zone is responsible for ensuring that when forming an image on the retina, not only the distance to the object is taken into account, but also the nuances of the ambient lighting conditions. This minimizes the need for the patient to use multiple pairs of glasses. In some cases, implantation of a multifocal IOL completely eliminates the need for a person to additionally correct their vision with glasses.

The multifocal lens is made of water-resistant and somewhat elastic material. It is rounded and has no sharp corners, which forms an image on the retina of acceptable quality. The optical mechanism of the multifocal lens is optimized to maintain sensitivity to increased depth of focus and increased contrast. All these factors make the patient's vision as clear as possible.

Which daily contact lenses are best?

We will try to answer the following key questions - what are the best contact lenses and what daily contact lenses for sensitive eyes should you choose?

From all of the above, perhaps everyone will put Johnson&Johnson[/anchor] daily contact lenses in first place. 1-Day Acuvue Moist is formulated with a material called Etafilcon A. It is highly permeable and retains moisture. In addition, these products are very soft, so they do not injure the cornea if accidentally displaced and are best suited for people with increased sensitivity. Next on the list are the Dailies AquaComfort Plus daily contact lenses from Alcon. Among other characteristics, they are equipped with a good UV filter and boast an excellent aspherical shape, which allows you to see the picture as clearly as possible, without distorted color rendition.

Biotrue ONEday from Bausch + Lomb is another popular contact lens that is made from HyperGel. This material is notable for the fact that its moisture content is about 78%, so you will never remember dry eyes and other unpleasant sensations. Today they are the “most” daily lenses, simply put, the favorites of customers around the world.

In turn, Proclear 1 Day soft contact lenses from CooperVision are developed using PC technology, which, in turn, guarantees optimal hydration of the cornea throughout the entire period of use and maximum comfort while wearing. All of the above daily contact lenses are the most popular, as evidenced by positive reviews from regular customers of our site. Many specialists in the field of ophthalmology also come to similar conclusions.

Risks and possible complications

IOL implantation is now a widely practiced operation with a proven technique and minimal risk of complications. Based on the results of a three-year study, the following figures were identified reflecting annual risks:

• loss of corneal endothelial cells - 1.8%;
• retinal detachment - 0.6%;
• cataract - 0.5–1.0%;
• corneal edema - 0.4%;
• the risk of eye infection, which in the worst case can lead to blindness, is 0.03 - 0.05%. This risk exists in all eye surgery procedures and is not unique to IOLs.

Other risks include:

• glaucoma,
• postoperative astigmatism,
• residual myopia or farsightedness,
• moving the lens inside the eye for one or two days after surgery.

One of the reasons for the above risks, namely the movement of the lens inside the eye, can be due to the wrong size of the lens (too short), as well as incorrect measurement of the eye. Toric IOLs should be positioned along the astigmatic meridians to correct the patient's existing astigmatism. Again, these lenses can move around inside the eye after surgery or be placed incorrectly by the eye surgeon. Repeated surgical correction will be required.

Which daily lenses are best for people with a specific lifestyle?

When you find yourself in an ophthalmologist's office, he is sure to be interested in your lifestyle and occupation in order to understand which contact lenses will suit you best. Many experts say that daily contact lenses are needed for people who:

• exercise regularly;
• often travel;
• they constantly go to the sea and love to be in the water;
• work in hazardous work;
• have had conjunctivitis or other diseases of the cornea.

Due to the short period of use, daily lenses do not accumulate bacteria that cause unpleasant consequences. They are convenient to take with you on the road, without worrying about having a special solution or storage container. These vision correction products are also suitable for those who are tired of uncomfortable glasses.

Production and fabrication, marking and design

Regardless of the purpose of aspheric optics, during its manufacture the location of the optical center of the product is taken into account, which normally should correspond to the center of rotation of the eye. To do this, the specialist carries out markings, which may include:

1. Determination of the pantoscopic angle, that is, the horizontal angle between the visual axis of the eye and the optical axis of the lens. Most often this indicator is in the range of 8-12 degrees.
2. Centering. The patient is seated and his head is pulled back so that the location of the lens in relation to the floor is strictly perpendicular. The center of the pupil is then marked on the template to help position the optical center of the lens correctly.
3. Determining the height from the center of the pupil to the bottom edge of the spectacle frame and marking it accordingly on the template.

The second important aspect in the production of aspherical optics is compliance with the required thickness and shape of the product. For the manufacture of spectacle lenses, special cast glass is used, the creation technology of which involves the formation of an ellipse or parabolic surface. As for CLs, they are formed from a mixture of special substances with a high level of refraction. Find out how long you can wear two-week contact lenses in this material.

The optical properties of aspherics are characterized by a smooth change in the radius of curvature from the center to the periphery, due to which, with a minimum thickness of the product, it is possible to achieve high optical power and enhanced contrast.

The appearance of an aspherical lens is thin, flat and graceful, compared to the excessive convexity of a conventional, spherical product. This also has its advantages from an aesthetic point of view - the eyes in such lenses do not appear too large or small, but will look natural and proportional.

If you experience discomfort when using contact lenses?

Even properly fitted daily lenses can be a noticeable cause of discomfort. Therefore, you do not need to endure, but should immediately contact a specialist if minimal discomfort occurs. You should not delay visiting an ophthalmologist if there is burning, itching or deterioration in image quality because this may lead to more serious problems.

Today, daily contact lenses are the safest optical products and a high-quality alternative to glasses. Some types, such as toric or night glasses, easily replace glasses, and some can even be worn at night. However, before purchasing, consult an ophthalmologist and undergo a full examination to identify the exact disease and the absence or presence of allergic reactions to a particular material. Strictly follow all the rules for wearing and using daily contact lenses and remember that your health is in your hands.

MagazinLinz.ru team

Main indications for lens replacement

Ophthalmologists call an intraocular lens an implant, which is known to ordinary patients as an artificial lens. The main indication for installation of an artificial lens remains cataract. The disease is associated with the loss of transparency of the natural lens. The lens becomes cloudy and stops transmitting sunlight, which manifests itself in a significant deterioration in vision. The operation can solve this problem by replacing the damaged cloudy lens with a completely transparent artificial one.

Installation of an implant is indicated in all cases of degenerative changes when the lens suffers from ophthalmic pathologies, damage or trauma. IOLs also help improve refractive error for myopia, hyperopia, presbyopia, and astigmatism.

Varieties

Ophthalmologists distinguish two basic types of multifocal lenses:

• refractive – the surface of the IOL is divided into zones with different refractive powers of light rays. They are evenly distributed from the center of the implant to its periphery. The effectiveness of such a lens depends entirely on the quality of illumination of the space and the diameter of the pupil;
• diffractive - lenses of this type work on the principle of redistribution of light fluxes. The functionality of the implant does not depend on the diameter of the pupillary zone and the level of illumination.

Diffractive IOLs are considered more convenient. They do not require the patient to make any effort to examine the object and do not require a long period of adaptation. In addition, diffractive lenses can be recommended for people with an abnormal pupil shape.

Both types of multifocal implants provide the patient with optimal vision and eliminate the need for spectacle correction. After the introduction of an IOL, the patient perceives objects well at close and far distances. But there is one “but” - objects located at medium distances can still appear blurry.