Which are the symptoms of astigmatism?
Astigmatic people have blurred vision. Consult your ophthalmologist.
How are lenses coloured?
Lenses are coloured by being immersed in special substances containing coloured pigments. Colour can be uniform over the lens surface or shaded. Lenses can be tinted in any colour.
What are aspheric lenses and their advantages?
Ophthalmic technology allows the production of special design, thinner and lighter lenses that ensure high quality vision over the entire lens area, even laterally. They also help in reducing eye deformation effect.
Which are the symptoms of hypermetropia?
People with hypermetropia cannot see clearly near and (to a less extent) far objects. Consult your ophthalmologist.
What is pre-calibration?
Pre-calibration is a special technology allowing lenses to be produced according to the chosen frame, reducing thickness and weight of the finished lens, thus obtaining beautiful and comfortable glasses.
What are wrapped lenses?
These lenses can be mounted on very curved frames, called wrapped frames. The use of wrapped frames, especially in the sun, ensures a higher protection from UV rays and atmospheric agents like wind and dust.
What is the difference between stock lenses and prescription lenses?
The manufacturing companies store ready-made lenses called stock lenses. Only the most common degrees of power are available for such lenses (approximately from +4.00 to -4.00 with cylinder +2.00). All the other ones are called prescription lenses and they are produced upon request. This means that delivery time of glasses with prescription lenses is a bit longer and their cost is a bit higher than glasses with stock lenses.
What are the photocromic lenses?
These lenses darken when they are exposed to UV rays. In darker environments, lenses become clear again in a short time. This occurs because the external surface of the lens is treated with a special transparent paint containing particles that are sensitive to UV light. When such particles are touched by UV rays, they activate and darken the lens. When UV radiation is reduced, the lens becomes clear again gradually. Photocromic lenses protect from UV rays.
The photocromic lenses offer several advantages: besides protecting from UV rays they adapt to the external light conditions, so that a single pair of glasses can be used.
Photocromic lenses do not replace sun lenses.
What are polarized lenses?
All the surfaces reflecting sunlight (snow, water, asphalt roads) act as a mirror, increasing the intensity of glare. To solve this problem, polarized lenses can be used. They select sun radiation decreasing its intensity when reaching our eyes and images can be seen more clearly.
Polarized lenses offer several advantages: best vision comfort and total protection from UV rays, that can seriously damage our eyes.
What are the symptoms of myopia?
People with myopia cannot see clearly far objects. Consult your ophthalmologist.
What is lens mounting?
This process allows lenses to be cut according to the right shape and size of the glasses frame. After being cut and shaped, lenses are mounted onto the frame. The geometrical centres of the lenses must match the centres of the user’s pupils.
What are rimless frames?
Lenses become the real frame. Temples and bridge are inserted into the lenses through special clips. When choosing these frames, it is necessary to use strong lenses with the same edge thickness (at least 2mm).
What are nylor frames?
On these frames, the edges of lenses are partially free. Lenses are fixed to the frame by a nylon thread running through a small channel in the lens edge. When choosing these frames, it is necessary to use strong lenses with the same edge thickness (at least 2mm).
What are the symptoms of presbyopia?
People with presbyopia find it difficult to focus on things that are at the normal reading distance. Consult your ophthalmologist.
UV radiation: how can I protect my eyes?
UV radiation is always present, even on cloudy days and it tends to increase as sunlight gets stronger. Always protect your eyes through dark, UV protected lenses. As a matter of fact, eyes must be protected from the sun like skin.
What is UV treatment?
With the UV treatment, a special transparent paint is put on the lens to prevent UV radiation from reaching eyes. The UV treatment ensure a full protection from UV rays and it is strongly recommended for sunglasses.
What is 1.5 organic resin or standard organic resin?
It is a transparent, lightweight and unbreakable material. It is the most commonly used material to produce lenses.
What is high-index 1.6 organic resin?
It is a transparent, lightweight and unbreakable material. Thanks to its chemical and physical features it is possible to obtain very thin, lightweight and strong lenses.
Considering the same power, a high index organic resin lens is approximately 25% thinner than a standard organic resin lens.
What is very high-index 1.67 or 1.74 organic resin?
It is a transparent, lightweight and unbreakable material. Thanks to its chemical and physical features and special production design, it is possible to obtain very thin, lightweight lenses.
Considering the same power, a very high index organic resin lens is approximately 35% thinner than a standard organic resin lens.
What is anti-reflective treatment? What are its advantages?
During anti-reflective treatment, some metal substances are put on the lens. These substances, which are invisible to the naked eye, can remove reflections and images from the lens surface.
Anti-reflective lenses are also treated with hardening, water repellent and anti-static substances.
The advantages of anti-reflective treatment are:
- clear vision through the lens
- high lens transparency, eyes are seen as they naturally are
- easier lens cleaning since water repellant and anti-static substances prevent dirt particles from depositing
- high resistance to scratches
- eye protection from UV radiation
What is lens hardening treatment?
With the hardening treatment, a special transparent paint is put on the lens external surface. After such paint dries, it increases scratch resistance.
Remember that the hardening treatment does not ensure total protection from scratches.
Glass lenses: why are organic resin lenses preferred today?
Even though glass lenses ensure high quality vision, they are very fragile, thus dangerous and much heavier than the organic resin lens that are very lighteweight and unbreakable. Considering the same power, a glass lens weighs twice as much as an organic resin lens.