People with poor eyesight, properly selected points will greatly facilitate inconvenience caused.
If you want to buy glasses price should not be the deciding factor, expensive glasses may not be suitable, therefore, the choice of points to take into account two criteria: the selection of lenses and frames.
The choice of lenses
Glasses are glass or plastic lenses. Each of these materials has its own advantages and disadvantages.
Advantages of glass lenses:
Not glaze over the entire service life;
Able to keep ultraviolet rays;
The use of photochromic additives, allows the use of glasses as sunglasses;
Application ar, polarization and antireflection coatings;
The disadvantages of glass lenses:
The material is quite fragile,
It is difficult to produce the lens with dioptrically double curvature, designed for people with astigmatism. Such people it is better to choose sunglasses with plastic lenses.
The glass is quite thick, which affects the weight. Such glasses can leave marks on the nose from the rim.
The use of lenses with photochromic impurities when changing the light causes a delay in the perception of reality, this occurs when a bright light should go into a closed room.
Advantages lenses made of polycarbonate plastic:
Plastic lens weight is almost two times lighter than glass;
Plastic lenses are less traumatic (harder to break before the traumatic fragments);
Have a wide color gamut;
Ease of production dioptric lenses with double curvature, which are used for vision correction astigmatism.
Read more about the glasses for astigmatism.
For vision correction astigmatism apply the so-called "difficult" points. In such glasses are used cylindrical-spherical lens. When a large difference in diopters when wearing these glasses possible dizziness and headaches.
Disadvantages lenses made of polycarbonate plastic:
Scratches are formed faster than glass lenses;
You need a more delicate treatment and tender care;
During the transition from cold to warm stronger misted;
Attract dust due to the accumulation of static charge.
The service life of plastic lenses is less than the glass;
When exposed to low temperatures become brittle.
The choice of eyeglass frames
When you select a frame, you need to consider that the nose of the person is one of the most sensitive parts of the body,
When choosing a frame, you need to try all possible options and to determine the following:
- Is it comfortable sitting glasses, isn't there pressure on the temples, the bridge of the nose or on Cousinia depression.
- Material for stops better choice of silicone, then points will be easier to take the form of the nose.
Glasses should not "take" from the nose when the tilt of the head and not parallel to the face.
- Pay special attention to the floor structure as the metal coating, in particular Nickel, can cause allergies.
the choice of frame material, keep in mind that plastic is less dogora than metal, but the life of such a structure is much lower.
- The frame must match exactly with the "base" between the eyes and the pupil is located in the center of the lens.
Correct choice points will hide the flaws in the appearance, such as: make the nose shorter, narrow cheekbones of the face to make it wider. We must not forget that rim is a fashionable accessory that enhances your style, taste and social status.