Which eyeglass lenses to choose?

It will not surprise anyone to hear me say that as soon as your vision starts to deteriorate, you should go to the optician and get glasses. What will surprise you is that not everyone does. There are many shops that sell glasses and contact lenses. You go to the shop and buy them. But not everyone does this. Buying without knowing your eyesight can be harmful to your health. The cost of making a mistake is huge. Your vision will not improve (and if it does, it will only be for a limited time) and your discomfort without correction will get worse. Just because you see a clear image when you try glasses doesn’t mean they’re right for you.

It’s important to know which lenses and frames are right for you. An optician can help you make this choice. The optician will carry out an examination and, based on the results, prescribe glasses to improve your vision, reduce stress and combat fatigue. Sunglasses are also selected in the same way if your vision is impaired.

What to look out for when choosing

During the examination, the patient should objectively answer the following questions:

1. How often do you need to wear glasses?
2. Do you wear glasses indoors or outdoors?
3. What kind of frames do you prefer?
4. What are the most typical weather conditions in your area: cool, sunny, cloudy, windy (do you need sun protection)?
5. Why do you need glasses: everyday use, driving, reading, correction of significant changes caused by congenital, acquired or age-related diseases.

Optical characteristics

Lens types can vary depending on the needs and requirements of the wearer. Here are some basic types of lenses:

1. Single vision lenses:
   Correct for one type of vision (distance or near).
2. Bifocal lenses:
   Combine two different focal lengths in one lens (for distance and near).
3. Progressive (multifocal) lenses:
   Provide a gradual change in power from the top of the lens (for distance) to the bottom (for near), with no visible boundaries.

Shape

• Spherical lenses: Conventional lenses with the same curvature across the entire surface. Used to correct farsightedness or nearsightedness.
• Cylindrical lenses: Lenses with different curvatures in different directions, used to correct astigmatism.
• Toric lenses: A combination of spherical and cylindrical lenses designed to correct astigmatism more precisely.
• Aspheric lenses: Lenses with asymmetrical curvature that provide a more natural visual perception and reduce distortion in the periphery.

Material

1. Glass or mineral. Durable. Resistant to deformation, high transparency and fogging. Benefits include protection from UV rays and high light transmission. Can be anti-reflective and shiny. Disadvantages. Not resistant to falls from height; heavy, may cause discomfort if worn for long periods; slow change in light transmission properties.
2. Plastic or polymer. Plastics are lightweight and have high impact resistance. They are difficult to break and do not deform at high temperatures. Glasses with plastic lenses are mainly used in specialised areas such as the metal industry. Their disadvantage is low transparency. Plastic glasses are available in different lens colours. Ophthalmologists recommend buying grey or brown ones to keep your eyes healthy.
3. Reactoplastics. These are organic compounds that harden under the influence of ultraviolet radiation. This results in a structure that does not deform when exposed to heat. Reactoplastics are widely used in modern optical components.
4. Thermoplastics. Under the influence of heat, thermoplastics turn into viscous-fluid substances. Lenses made from these materials are injection moulded.

Refractive index

The refractive index is an index that depends on the thickness and volume of the lens. The higher the index, the lower the mass and thickness. A high RPI is used for rimless frames. High index lenses are used to correct the vision of young children. Products with a high refractive index have a low ability to transmit light. Another disadvantage is their high cost. However, high index materials are more often recommended than others because they have special coatings that provide comfortable optics, eliminate glare and provide light. The base depends on the material. Glass and mineral can be produced with RPs from 1.5 to 1.9. Plastics – 1.49, 1.53, 1.56, 1.59, 1.61, 1.67, 1.74. Polycarbonate – 1.59. Tribex – 1.53.

Type of coating

To keep your eyes healthy and your vision sharp, lenses are coated with special substances. They protect the retina of the eye from adverse effects. There are several types of coating:

Reinforced. Used on most types of lenses. To increase strength and wear resistance, the coatings are treated with special substances on both sides. This allows the product to withstand mechanical impact and last longer. Lenses with a reinforced coating will not be damaged by high pressure, falling from a height, contact with sharp objects or metal (keys, coins).
Brightening. The coating reduces the reflection of sunlight from the glass surface, protects the eyes from glare, reduces ultraviolet radiation, gives brightness and transparency to the image. The properties of this coating depend on the number of layers.
Anti-glare. These coatings reduce eye irritation caused by flashing lights, such as reflections from car headlights and mirrors. They are especially recommended for drivers who drive at night. They reduce eye strain during prolonged computer work, reduce tear production, dry the mucosa and reduce the risk of vision loss.
Hydrophobic. The coating increases resistance to fogging. Vision is not affected by sudden changes in temperature. Protects against sand particles, oil spills and fingerprints. Antistatic properties prevent dust from adhering to the lens.
Multifunctional. Coatings that have several effects at once.

Lens colour

Lenses can be coloured to enhance the aesthetic effect. This option does not affect the performance of the lens, but some shades may affect the visual system:

Yellow. This is an illuminating colour. It increases the transparency of the lenses and improves image quality. It makes objects look better and more natural.
Red. This colour stimulates the activity of sensitive cells and increases reaction time. Red lenses are suitable for light weapon training and work.
Blue. Cold colours reduce eye fatigue and have a calming effect.
Green. Often used in sunglasses. This colour has a beneficial effect on the nervous system and improves the transmission of nerve impulses.

Occupations

Office workers. Office workers spend a lot of time in front of computers. Being in front of a screen all day can be very tiring for the eyes and exhausting for the whole body. Optical elements for office work should help correct near and far vision. Their advantage over conventional lenses is that they are suitable for reading at a distance of 40 cm or more. Office workers’ eyes focus on screens and documents many times a day. Multifocal lenses should be purchased. They are not designed for viewing distant objects and are not recommended for outdoor use. For people with normal vision, the use of ‘yellow’ glasses can compensate for the flickering of the screen and reduce eye strain during long periods of computer use.

For drivers

Progressive lenses should be chosen for driving. They allow you to see dynamic vision and distant objects more clearly. Drivers with presbyopia can use universal design glasses. Peripheral vision is very important when driving. Some manufacturers offer special designs tailored to the driver’s eyes. In addition to near vision, these products offer extended ranges of distance, intermediate and dashboard vision.

Choosing lenses for sunglasses

Sunglasses have an aesthetic function as well as protecting the eyes from ultraviolet rays. Plastic lenses are a good choice for this type of accessory. They require some maintenance, but are safer to use and provide excellent protection from sunlight. Sunglasses can be photochromic or totally dark. The former darken when exposed to sunlight. Alternatively, some manufacturers offer plastic lenses with a high index of refraction. These are the thinnest options available and also the most aesthetically pleasing. If you drive, do not buy glass lenses to avoid injury and damage.

Shapes and frames can vary and should be chosen according to style and type of clothing and face shape. Use inexpensive materials such as plastic or non-precious metals for frames. Steel and plastic are convenient and inexpensive. Titanium is durable, strong and light, but expensive. Silver, gold and platinum look good and cost more, but are not as practical as titanium.

How to buy glasses

• When buying a pair of spectacles, you should pay attention to the temples, clips, optical surfaces and other elements.
• Quality models do not distort the image and the human eye when worn.
• Look for transparent and smooth surfaces. Scratches, roughness and microcracks cause eye strain and distorted vision.
• There should be no gaps or misalignments within the frame.
• Make sure that the optical elements do not protrude from the frame.
• Check that the lenses are evenly convex.
• Check the temples. The temples of a good accessory should be smooth. Try opening and closing them a few times. If they are too tight, try another pair. You can check the lugs by placing the glasses on a flat surface. The temples should be in the same plane.
• Always try on glasses and check that the temples do not pinch your nose or move when you lower your head.
  The frame should be chosen according to your optician’s prescription. It should match the distance between your pupils and be symmetrical.

Most popular manufacturers

The best manufacturers have been chosen for three types of lenses: bifocal, office and progressive.

OSA bifocal lens manufacturer.
This product is manufactured using high technology. It is made from high quality polymers and has UV, anti-reflective and multi-coating. It is available in clear, gradient and photochromic versions.

WEIYA
Chinese brand WEIYA develops lenses specifically for people with active lifestyles. Made from high quality polymer glass, these lenses are lightweight and ultra-thin. Low distortion and wide field of vision. No external damage. Special coating protects against scratches, dust, UV and glare. Can also be coloured or clear.

Russian manufacturer using Top Vision Free Form technology
The products are made of high quality plastic and are resistant to abrasion and wear. UV, anti-reflective, mirror and anti-static coatings are available.

Israeli brand Shamir produces lenses using the latest technologies to ensure comfort and aesthetics.
The company uses FreeForm technology and offers a wide range of coatings. Office lenses These lenses allow you to see both far and near. They are usually prescribed for people who spend a lot of time working at a computer.

ESSILOR
This brand produces corrective lenses to improve/maintain vision when working at a computer. They are also suitable for relaxing and reading. The products are made of high quality polymer and have anti-reflective and anti-hardening coatings.

The Japanese brand Nikon produces lenses for eyeglasses and photo and video equipment.
The lenses are of high quality and only high quality materials are used in their production. All products are protected against moisture, UV rays, dirt and dust. They are suitable for prolonged reading and computer work.

HOYA.
The company produces lenses for viewing objects at short and long distances. They have protective coatings against UV radiation and blue radiation from equipment.

SEIKO INDOOR PC
Suitable for reading and prolonged computer work. Reduces eye burning, fatigue and muscle strain. They have a much wider field of vision than standard glasses. Made of plastic and coated to prevent blue radiation from equipment.

Rodenstock progressive lenses.
This German brand produces high quality lenses that meet international standards. The lenses are coated with a special lacquer for extra protection.

Zeiss
This German manufacturer produces not only spectacle lenses, but also microscopes, medical instruments and binoculars. The price range of this brand is above average. The lenses meet the needs of every buyer, there are many models with different coatings. They are protected against UV rays, darkening and glare. High prices are justified by excellent quality and reliability.

KEF.
A Chinese brand that makes products to German standards. Relatively low prices but high quality, protection from UV, blue light from equipment, dirt and dust.

Tokai
Japanese brand known for top quality, innovative technology and R&D. Coating protects against UV, glare, blue light from equipment, dust and dirt. Production technology based on oxidation protection.

Conclusion

Consult your optician. He will be able to check your eyesight and help you choose glasses and frames. Ready-to-wear lenses have average universal parameters. They are only suitable if you rarely wear glasses and your dioptres are round. For example, if your dioptres are less than 3.75, you shouldn’t use them; if they are less than 1, you can, but it’s still better to have them made to measure.

Try the glasses on before you buy them. Correction is only possible if the glasses are comfortable to wear, fit snugly and do not slip when you move. If there is a difference in your vision when you change glasses, you may feel a little dizzy at first. This will pass within a few days. If it does not go away, you should consult your optician.

Bifocal and progressive glasses are available with thin frames. They improve vision for problems such as short-sightedness. Plastic frames are suitable for prescription glasses. They can partially compensate for the weight of the lens. Lenses are the main working element of prescription glasses. Consult your optician before buying new glasses.

Additional tests will help track changes over time and select optical components that reduce eye strain and slow vision loss. An optician will select the glasses, record the dynamics of change over time, and make recommendations for maintaining eye health.