Main page > Worth to know

Worth to know

Here are the most frequently asked questions about eyesight and answers to them.

Eye examination


Register

Do I have astigmatism?

Astigmatism is a deformation of cornea which is the reason why light does not focus on one point of the retina. You can see it as a distortion or blurness of a text or an object's image. You are always checked for astigmatism in an eye examination and it is corrected if necessary with a suitable spectacle  lens. The surface of an astigmatic eye is different in different directions and so is the need for the optical strength of the lens. In this case the lenses are ground cylindrical (shortened syl or cyl or c.) which means that the lenses have two different strengths (e.g. in vertical and horizontal direction) and the strength of the lenses is shown for example this way: sf +1,0 cyl -0,25 ax 90°.

 

How do I know that my eyesight has weakened?

Eyesight has weakened if, for instance, watching TV or reading a text has become difficult or you do not see traffic signs or bus numbers well. Headaches can also be a sign of a weakened eyesight, especially if they appear at the end of the day or after a lot of intensive near vision work.

 

How to interpret the results of an eye examination?

The result of the eye examination will be the knowledge of your refraction according to which the far vision strength is determined. The checkup will also show if you have astigmatism and the need to correct it. Far vision strength is the basis for a possible need to prescribe near vision spectacles, the close add for which is shown separately.

The size of the close add is affected by your usual working range  and the adaptability of your eyes to see at a closer distance. The need for the close add changes with age. The overview of the eye examination also shows the sharpness of your vision with spectacles and without.

 

Ageing and eyesight

The elasticity of the eye lens deteriorates with age – you notice this when reading as the text gets hazy. Reading spectacles with necessary strength help to make the text clear again.

 

What is vision?

Vision is the reflection of the visible object on the retina of the fundus of the eye. Light rays entering the eye are focused by the cornea and lens to form an image on the retina. The retina contains millions of light-sensitive cells which convert the image into a pattern of nerve impulses. These impulses are transmitted along the optic nerve to the brain. Information from the two optic nerves is processed in the brain to produce a single coordinated image.

 

How often should I check the eyesight?

Eyes should be examined at least once in two years. Eye examination is a simple and quick procedure at Instrumentarium stores. In addition to the eyesight, our optometrists also take care of the wellbeing of your eyes. If necessary, we will make an appointment with an ophthalmologist for you. It is advisable to visit an ophthalmologist at the age of 40 at the latest and then once in every 3 years.

 

How is eye examination carried out and how long does it take?

During the eye examination different tests are performed depending on how you see and which spectacles or contact lenses you will probably need to correct your eyesight.

Eye examination determines how well you see with your eyes and to what extent spectacles improve the eyesight. First of all, eye refraction is checked which determines the strength of far vision spectacles. Then your near vision ability is tested.

The eye examination takes about 15-30 minutes.

Spectacle lenses

Why are spectacle lenses prices so different?

Spectacle lenses can be mono or multi focal and that is the main factor affecting the price formation. The choice of various materials and surface coatings affecting the weight and durability of the lenses also influences the price.

 

Why does an optometrist always advise more expensive spectacle lenses?

More expensive eyeglasses lenses are of a higher optical quality and thus better for your eyes. Lenses of a more expensive price class are often made of a durable and lighter material, wear long and are more comfortable to use. Hard surface and antireflection coating improve vision as the lenses do not get scratched so easily and the image is clearer. You see well with discounted price spectacles too but they lack various properties that improve your vision.

 

How do various surface coatings differ?

Surface coatings improve your vision quality and lenses durability. Hard coating enables plastic lenses to endure scratches better. Antireflection coating decreases the glare of the glass surface and reflections that tire the eyes. It also adds to the light strength of the spectacle lenses i.e. eyes get a clearer image of the object. The smudge-resistant surface helps to keep the lenses clean as soil and smudges do not leave traces so easily so you see more clearly.

 

Am I long- or short-sighted and do I need multifocal spectacle lenses?

If you see well into the far distance, you are long-sighted. A young long- sighted person sees as well at a near distance. If reading is hard and the text seems hazy, the reason may be weariness of the eye lens (also at a younger age) caused by near vision work or weakening of the eyes adaptability generated by ageing. In this case you need spectacles for near vision.

If you do not see far into the distance, e.g. cannot see clearly traffic signs or bus numbers, then you are short-sighted. You need spectacles for distance vision.

You need multifocal spectacles if your eyes need optical correction of diferent strength to see at a closer or farther distance. Multifocal eyeglasses are useful if you need spectacles for reading but your work sometimes requires you to look into distance without taking the spectacles off.

More about spectacle lenses

Eye flexibility deteriorates with age, you notice it when reading or doing some work requiring precision – you do not see so well when becoming older. If you move the book farther away, the text becomes clear again. In this case you need special spectacles for near vision work and during the eye examination a necessary close add will be determined.

 

What is the best solution for short-sightedness?

A good solution for short-sightedness is monofocal spectacle lenses which give a good vision range. Monofocal glasses are a good choice when there is a lot of work and reading and this always happens at the more or less the same distance.The strength of the spectacles is always prescribed according to the individual needs of your eyes and working distance.

Common spectacles (bi- or multi focal) are suitable for reading, however their near vision area is smaller than that of monofocal spectacles.

Special work or office spectacles enable to have a sharp vision of several closer distances. They are made considering your necessary work distances and the spectacle lenses are ground to your individual strength.

The reason for neck and head pain is often wrong spectacles or false correction of eyesight! Make sure your work glasses are the best possible!

 

Which spectacles lenses are good?

Good spectacle lenses are optically precise with no distortions when looking through them.

 

Why and how do various spectacle lenses differ?

The choice of spectacle lenses material is important for different strengths: it is better to make lenses of greater strengths from thinned material to avoid accumulation of too much weight on the nose. The optical strength of the lenses is determined according to the purpose of the spectacles usage.

Monofocal spectacle lenses have the same strength all over the whole lens as e.g. in the so called 'common glasses' with which you see either far or near. The vision range i.e. how far or near you can see is affected by the lenses strength, adaptability of the user's eyes and eye lenses elasticity – called accomodation.

Spectacles meant for near range may be monofocal (in this case one sees the closer area determined by their strength and the user's eye adaptability), bi- or multi focal.

Bifocal spectacles have two different strengths – through the upper part of the lenses you see farther and the 'slot' in the lower part is for reading where the close add, i.e.suitable strength for reading, is inserted fitting your eyes needs.

The close add for multifocal spectacles is designed with smooth transition, i.e. the lenses have a different strength for reading, but the border between the areas is not visible.

 

See well when driving – protect yourself from blinding

Eyesight correction has to be the best possible in traffic for your own and others' safety's sake, so that you see road signs and other traffic participants at the right time. Check the strength of your driving glasses regularly. You may often need spectacles of a different strength for night driving. Make sure the frame is strong and fits well. For safety's sake it is good to have a reserve pair of spectacles.

Being blinded can be avoided by using protective sunglasses.The shade of photochromic lenses changes according to UV-radiation – but the darkening will not occur in a car as the window shields do not let the UV- radiation through. Polaroid lenses help to avoid the reflections from water or road surface.

 

What is 100% UV-protection?

UV-protection means that the spectacle lens does not let the ultraviolet (i.e. under 400 nm of the visible light) radiation to permeate. UV- protection is necessary to avoid the harmful effect of ultraviolet radiation. The damaging UV-radiation for eyes is reflected in an especially big amount from the snow or water surface in a sunshine weather.

 

How does the sunlight affect eyes?

Sunlight contains much UV-radiation, so you have to especially protect your eyes with sunglasses when moving on the snow or water. Bright light blinds you and disturbs your vision. Excessive UV-radiation may quicken the appearance of cataract.

 

How do various multifocal spectacle lenses differ?

Various multifocal lenses have areas of far and near vision (i.e. the upper and lower part) which are ground according to different eyes needs. Distortions caused by the lens structure appear on the edge area of multifocal lenses. Precise optical grinding enables to shift the location of the distortion, thus enlargening the area of either far or near vision. Large near vision area is good for work at a closer distance. However, if it is more important to see far into the distance, then it is advisable to choose the lenses with a larger far vision area.

The strength of multifocal lenses changes smoothly from the upper to the lower part with the greatest closer strength. The transition area can be used for intermediate vision (e.g. 1-2 m). The main difference between multifocal lenses is how wide or long the transition area is and how well one can use its strengths for seeing.

Narrow and small frames need specially designed multifocal lenses which are ground so that the lower reading area is large enough.

Spectacle frames

Spectacles for work – does the employer compensate the cost of work spectacles?

Office or other work spectacles may be compensated by the employer. Office work requires near vision spectacles. The weaker the eyes adaptability has become with age, the more changeable may be the necessary near vision strength for different working ranges. In this case one needs such spectacles at the work place which guarantee a clear vision of the whole workplace. It may be, for instance, multifocal near vision spectacles. A professional optometrist can find the best solution considering your sight and working conditions.

 

Customers' feedback

You are welcome to give your feedback here

Customers who have purchased spectacles and whose contacts have an e-mail address will receive an e-mail invitation to participate in a client satisfaction questionnaire one week after the purchase. The e-mail has a password enabling the customer to answer the questions electronically.

 

What is the satisfaction guarantee for spectacles?

1. Satisfaction guarantee

New spectacles have a two-month satisfaction guarantee. If you are not satisfied with the purchased spectacles for any reason, you can exchange them for new ones at the same price during two months, paying only for the spectacle lenses. If you purchase more expensive spectacles you have to pay the price difference.

2. Two-year free spectacle maintenance

We provide a two year free care for your spectacles starting from the purchase day. It includes tightening the screws and bending the temples. Normal wear and tear is not subject to the free maintenance. If the bending appears to be complicated and the spectacles may break, we inform the customer and reserve the right to refuse to carry out the work.

Read more about our loyal customer programme

 

Spectacle repair

We repair broken spectacles if we can. Bring your broken spectacles to our store and consult the assistant. It is not always possible to fix them in your presence while you are waiting as some works may take more time and are carried out in the workshop. Our stores offer ordinary maintenance service such as bending frames, exchanging nose pads, tightening the screws and the like. The repair and maintenance works are carried out according to the pricelist. Instrumentarium's loyal customers get a discount.

 

How to take care of spectacles?

Spectacles are washed with lukewarm water and a gentle detergent, spectacle lenses are dried with a soft cloth. Spectacle cleaning cloth is convenient on a trip or when washing with water is not possible.

Spectacles are kept in a case protecting them from impact and scratches.

Contact lenses

Using contact lenses

You will get a detailed and personalized instruction for contact lenses use from our optometrist – follow it carefully.

Can I use contact lenses?

Contact lenses are suitable if your eyes are healthy – the suitability of lenses for eyes is always tested by an optometrist before trying the lenses. Nowdays contact lenses are available in almost all strengths, for astigmatic eyes and as multifocals.

If you are not an adult yet, discuss with your parents and ophthalmologist or optometrist whether contact lenses is a suitable solution for you – you should be able to take care of the lenses and insert and remove them yourself.

 

What contact lenses to choose?

Different purpose and time of usage of contact lenses determine which lenses are suitable.

Disposable contact lenses are good for occasional use, on a trip or for situations when cleansing the lenses is hygienically complicated.

The range for everyday usage is wide: lenses meant for the whole month or a couple of weeks, which can be cleaned in the evening and kept in a special container overnight.

Contact lenses meant for continuous wear are convenient for 24 hours use if they suit your eyes. Start using the lenses under the control and according to the instructions of your ophthalmologist or optometrist, and change old lenses for the new ones at the right time. So your eyes will stay healthy and the lenses are always clean.

Children's eyesight

Does my child see well?

It is possible to follow child's vision development. If a baby does not show any interest for near objects it may mean it does not see them. Sense of sight  develops together with coordination of eyes, hands and body. So the reason for child's clumsiness may be weak eyesight as the perception of distance and depth is inhibited.

 

Eyesight and concentration

Good eyesight helps to focus on the activity at hand. If a schoolchild does not see well what is written on the board, they can abandon following the teacher altogether. Symptoms of an eyesight disorder may be rubbing the eyes, headaches, mixing up letters when writing, following the text with the finger when reading and even unwillingness to read. It is good make sure  before the start of the school that the spectacle frames are of the right size and lenses are not scratched. The spectacle lenses may have just become too weak with age. An optometrist is allowed to prescribe spectacles to children starting from the age of 8, however, if there is a need, the child is sent to an ophthalmologist.

 

Do I have to check my child's eyesight – how to notice that my child does not see well?

Children's eyes and normal development of eyesight have to be checked already at an early age. Eye examination with the specialist is necessary if you notice any aberration in the position of eyes (mis-alignment of the eyes) or if the child does not distinguish small things or details.

Uncorrected refraction disorder can lead to a persistent weak eyesight which means that the child's vision does not develop properly and is often impossible to be corrected later even with the help of spectacles.

 

Eyesight during early years

The near vision of a newborn baby is weak but during the first year it develops until the normal level. It is interesting to notice how the child interprets what it sees. At the beginning the child sees only images and silhouettes, then starts to recognize them and later learns the colours. Together with the development of eyesight children learn to coordinate the movements with what they see.

 

Eye examination at the age of 3 at latest

You should check children's eyesight with the ophthalmologist at the age of 3 at the latest. At the time it is still possible to determine the disorders of eyes development and treat them. Before starting the school and during schoolyears the child's eyesight should be examined once a year.

Ophthalmologist

To visit an optometrist or ophthalmologist?

An optometrist is a professional with a thorough specialist training who is an expert on solutions to eyesight problems, prescription of spectacles and contact lenses. An ophthalmologist is a medical specialist with higher education who diagnoses and treats eye health problems.

You can visit an optometrist to have your eyes examined and get spectacles or contact lenses. If they find it necessary, you will be sent to an ophthalmologist for medical tests.

An optometrist can carry out eye examinations of children over the age of 8 and people with no eye operations or diagnosis of ocular diseases.

Children under the age of 8 should have their eyes examined by an ophthalmologist. Adults at the age of 40-60 are advised to regularly  check the state of their eyes once in every two years. People over 60 should visit an ophthalmologist once a year.

If you know about hereditary eye diseases in your family (e.g. glaucoma), you should go to check the health of your eyes to be sure.

How to treat and prevent eye problems – dryness, stinging, light oversensitivity and wrinkles around eyes?

You can get special moisture drops from an optometrist to relieve eyes dryness and irritation. They are safe and soothe the eyes. If your eyes are red and excrete pus, you should check with the ophthalmologist for an eye inflammation.

To help the light oversensitivity there are tinted lenses with different stages of darkening to cater for all needs. One possible solution may be photochromic lenses – consult with the optometrist what fits you best.

The wrinkles around the eyes may appear from squinting in bright light or straining your eyes to see better. Make sure the strength of the spectacles suits the eyes and protect the delicate skin of the eye area with sunglasses that cover it.

 

How to make an appointment with an ophthalmologist?

You can make an appointment with an ophthalmologist in the same way as with an optometrist to have your eyes checked. The quickest way is to call the store. You can also book by e-mail.

 

What are the most wide-spread eye diseases and their reasons?

The most wide spread serious diseases are cataract and glaucoma. People of any age can have eye inflammation – this is treated with eye drops prescribed by the eye doctor.

Some of the ocular diseases are hereditary, so, if you are aware of any such disease in your family, visit the doctor regularly to examine your eyes. The early diagnosis of an eye disease can help to slow down its development if it can be treated by medical means.

The reason for development of a cataract may be excessive UV-radiation, so the people spending much time in the sunlight have to protect their eyes with sunglasses.