Optics and contact lenses

Optics

If the patient has prescription for eyeglasses and is need to acquire glasses, experienced and knowledgeable specialists of the „ Latvian American Eye Center” will advise on the most appropriate type of eyeglass lenses, evaluating degree of visual refraction, patient’s daily habits and lifestyle, and will help to choose the most comfortable and appropriate spectacle frames, as there are cases when it is impossible to insert the lenses matching to the patient’s vision in the beautiful spectacle frame already purchased (for more details see subchapter “What is important to know about spectacle frames?”)

Glasses mostly are made within one day. Making of sophisticated glasses takes longer time and the patient is informed in timely manner.

The opportunity to acquire also optical sunglasses, optical sports glasses and optical goggles, as well as EU standards -compliant protective glasses and goggles – masks and face shields is offered to the patients in the “Latvian American Eye Center” Ltd.

What types of eyeglass lenses are available to the patients?

By surface design

Depending on surface features, spherical, aspherical or toric (cylindrical) eyeglass lenses are available. Spherical lenses are classic and more common type of eyeglass lenses, which are designed for correction of myopia, hyperopia or presbyopia. Aspherical lenses are thinner and less curved compared to spherical ones. They provide wider field of vision and allow for preventing image inaccuracies, and, in many cases, slow down occurrence of eye fatigue at prolonged exertion. Aspheric lenses are also designed for correction of myopia, hyperopia and may be indicated in patients with astigmatism. Toric spectacle lenses, also called astigmatic lenses, are specially designed to correct astigmatism.

By the focus distance

Monofocal spectacle lenses. In the center of the monofocal spectacle lenses, a single optical power is set for vision correction either for near or distance vision. Mostly young people are using monofocal eyeglass lenses for vision correction both for near and distance vision correction. But after 40 years of age, glasses of different strengths are often required at different viewing distances, and if the patient uses monofocal spectacle lenses, vision will be blurred at one of the distance.

Bifocal spectacle lenses. In the bifocal spectacle lenses, two optical powers are set, in the top part – for distant vision (taking about 2/3 of the lens) and in the lower part – for near vision to facilitate activities such as reading, writing, knitting, etc. While at medium distances the image is usually blurred.  If necessary, optical powers may be set upside down that is important for certain professions, such as car mechanics, under the vehicle.

Progressive (multifocal) spectacle lenses. In the progressive spectacle lenses, the gradual change in optical power from distant to near vision is set. Such lenses provide good vision at any distance; however, when using them, the patient should expect to have to learn to control eye movement in a vertical direction to find the required optical power in the lens. It should be noted that peripheral vision with the progressive spectacle lenses may be blurred and the image distorted that makes it necessary to shake the head.

By coating

There are many different types of lens coatings that are used to customize the eyeglasses to the patient’s individual needs. In addition, each optics firm offers its own specially advanced lenses and their coatings, which are produced applying different technologies, but their essence is similar.

Hard coating.Scratched lenses have a significant impact on the quality of vision and therefore a hard coating is developed that is embedded in both sides of the lens, making it harder and more resistant to scratches and impacts. However, it should be remembered that no coating will provide protection against serious damage. Standard organic hard lenses are democratic option in terms of price level and can be additionally coated with UV protective layer, as well as tinted in any tone at patient’s preference.

Anti-reflective (AR) or anti-glare coating. Anti-reflective coating increases the amount of light entering the eye and reduces the amount of light loss caused by light reflection from both surfaces of the lens. Such lenses also provide a good cosmetic effect, as the lenses are virtually invisible. The lenses with anti-reflective coating allow more light to pass through that is useful both for car driving during dark of the day and working at the computer when troublesome reflections may occur. Anti-reflective coating provides clearer visibility, better contrast and depth of image, reduces eye fatigue, for example, when working at a computer for long time period, especially in rooms with multiple and various light sources.

Hydrophobic or anti-fog coating. Provide water repellency from the lens and accelerated defogging of the lenses, from example, when entering from outdoors into rooms in winter conditions. It is important to take into account that no lens coating ensures that the lens will not fog up at all, however, thanks to the latest technology, the considerably faster defogging of the lens has been achieved.

Coating with UV protection. High index (thinner) lenses as well as lenses with anti-reflective coating additionally prevent the sun’s ultraviolet radiation, which has a negative effect on eye health. The lenses with such a coating, like sunglasses, prevent UV radiation from reaching the eyes. It should be noted that the simplest corrective lenses do not have this coating.

Photochromic coating. Spectacle lenses with a photochromic layer, popularly known as “chameleons”, automatically change color and become dark when exposed to sunlight, depending on the intensity of UV radiation and temperature. When being indoors, they gradually become translucent or almost translucent. Photochromic lenses are ideal for people who are sensitive to sunlight. It should be reminded that these lenses will not be dark when driving a car because the car glass blocks UV rays. However, a solution has been found, and photochromic lenses are available which, even in the car, tint, but less intensely than outdoors. Such lenses will also be darker indoors. It is important to note that photochromic lenses are darker in winter than in summer. The most important benefits of photochromic lenses are 100% UV protection and visual comfort regardless of the level of illumination.

Tinted coating. The lenses can be tinted or darkened that is necessary for improving vision under intense lighting conditions. Tinted coated lenses are used for optical sunglasses. The tinting protects the eyes from bright light and adjusts the intensity as needed – light tinted lenses can be used indoors, while for example, high in the mountains very dark spectacle lenses are required and, of course, with UV protection.

Blue coating. Protects the retina of the eye from the negative effects of blue light emitted by smart devices, improves visual contrast and reduces fatigue working at the computers and with smart devices.

Polarized coating. Lenses for sunglasses that remove blinding glare from surfaces (such as water, snow and ice, road surfaces, etc.). Lenses are especially suitable for drivers, fishermen, mountain climbers and water sports enthusiasts.

Types of eyeglasses according to the conditions of wearing

When using the eyeglasses, patients should not put up with restrictions caused by them as there are developed various types of special eyeglasses according to the conditions under which they are used.

Optical swimming goggles. Ideal for active people who need to wear glasses or contact lenses. Such goggles provide good visibility and eliminate the risk of dangerous eye inflammation caused by swimming with contact lenses.

Optical sports glasses. Suitable for a variety of sports, such as cycling glasses with specially curved spectacle lenses serve as both an optical corrector and goggles.

Optical sunglasses. People who use optical glasses correction should not forget about the use of sunglasses as it is possible to use optical sunglasses that not only have tinted lenses but also the optical correction needed to the customer.

Clip-on optical spectacle lenses or “clips”. Easily affixed and easily removable tinted or polarized eyeglass lenses that can be clipped-on existing optical glasses.

For the use after eye surgeries, such as cataract or laser surgery, special postoperative glasses have been developed, available with or without sunscreen, and protect the eyes from a variety of eye irritants that can adversely affect the outcome of the eye surgery performed. There are also special nighttime goggles for use at dry eye syndrome.

What is important to know about spectacle frames?

Contrary to popular belief, the spectacle frame is not just a stylish element that can highlight a person’s personality and style. It plays a vital role in ensuring the patient’s visual comfort in everyday use of corrective glasses.

The most important parameters when choosing a frame are the frame size, for example, whether it is not too wide or not rest against the cheeks, and its distance from the eye (vertex distance) – at what angle is the front part of the frame in relation to the eyes, and whether the eye is in the center of the frame or maximum close to it. Of course, when choosing eyeglass frame the assessment should also be made whether it is firmly based on the nose and the length of the arms of the frame length is appropriate.

One of the things that is important to note is that the frame with the corrective lenses may result in a look that is different from the one tried on with demo lenses at an optician’s salon. Likewise, the weight of spectacles with corrective lenses usually increases slightly. Moreover, it is not uncommon that due to the patient’s refraction it is impossible to insert eyeglass lenses of the optical power specified in the prescription into the selected frame. For example, in the case of high degree of nearsightedness, it is advisable to choose a spectacle frame with a smaller window, as the edges of minus-type lens are thick and may even be thicker than the frame itself.

That is why it is essential that the right choice of eyeglass lenses and frames are made by a certified and trained specialist who, unlike the patient, knows all the nuances of the glasses and their frames.

Useful additional information for spectacle users

  • New eyeglass wearers are often worried about getting used to this kind of correction. This question cannot be answered unequivocally - the main thing is not to be afraid and to try, because only this is the way to understand whether this type of vision correction will be suitable for the patient in the long run. If a suitable vision correction tool is selected, it should only result in comfort, not discomfort.
  • There are a variety of abusive prejudices about the use of spectacles in the public, especially among young people that make many who are prescribed this type of vision correction to be ashamed of the need to wear glasses. Unfortunately, this is also the reason why young people often disregard doctor's recommendations and wear glasses occasionally. However, one should be aware that glasses can not only serve as an optical correction tool, but also as a cool and stylish accessory. Eyeglasses have long become a fashion item, not for nothing that they are used by many celebrities (even without visual impairment), because it is a good way to give some zest to the looks. Moreover, many young people who have good vision, purchase glasses only as accessories for accentuation of their style. That is why there is a wide and varied range of not only frames but also eyeglass lenses, so that every patient can find the best option for his or her appearance and lifestyle.
  • Optometrists and eye doctors are often faced with patients' view that prolonged wearing of spectacles impairs vision with time, but this is a false belief - a worsening of vision is in no way connected with the use of spectacles. On the contrary - they only improve visual comfort.
  • If glasses are prescribed to the patient, but he or she chooses not to use them for various reasons, it is expected that asthenopic complaints - headaches, eye fatigue, blurred vision, and so on, cause of which the patients tend to attribute to factors other than non-wearing the glasses.
  • The primary function of eyeglasses is to help us see clearly and also to develop vision in young children, for example in the case of amblyopia. If the glasses are indicated to the child but not used, this can lead to the development of amblyopia or lazy eye which, unfortunately, is no longer treatable without the timely application of vision correction tools (glasses and / or occlusion), and most often one eye is unable to see 100% neither with nor without spectacle correction.