|Diving mask ? the underwater world of Windows|
|"The mask" face mask is a diver in the water window. Ray Ban Outlet diving side mirrors have a nose for balanced pressure capsule and prevent water from entering the nasal cavity. See through the mask of the object under water 0.33 times larger than actual size. People who need vision correction can match myopia lenses.|
Because of the greater density of water than air, the human eye cannot focus directly in the water, so the diver must wear mirror above, retain their air cavities in the front of the eye, so divers in the water can in normal view.
Try to open their eyes in water and can see only a blur of scenes, this is because the density of water than air, the light refraction in water. The focal length of the eye is based on the light in the air conditioning, so the mirror makes your eyes retain a cavity, so that you have clear lines of sight. Face mask and swimming goggles, a major difference is that the former covers not only the eyes also looking nose, this is because when diving to prevent squeeze, need to balance pressure within the nose, so cannot use swimming goggles for diving.
General mirror by hardened safety glass Cheap Ray Ban Sunglasses lenses, fitting rubber or Silicone base sides of the face, and can be composed of fixed-position adjust the headband. Enhanced safety glasses to prevent broken into slender glass fragments to be at high risk. Group materials Silicon than rubber, this is because the durable silicone rubber 3-4 times, not easy to make skin more soft and comfortable. Some face mask has a drain valve; a check valve is used to exclude the face mask in the stagnant water. Select the mirror are the two most important points is the right to be comfortable or not, other equipment, too. Not a suitable face mask may be water leakage may also be caused by allergies, less diving fun.
Test mirror right or not, just gently put the mask on the face, (without top) and then breathe in through your nose, a suitable face mask on sticks in the face until you breathe. Another point to note is that making sure you can easily squeeze the nose outside the mirror. Mirror styles varied, micro lenses, two lenses and lens for many species, usually only two lens models equipped with corrective lenses.
Available before using for the first time in the mirror stained with toothpaste, soft cloth, gently wipe the lens to remove the protective film on both sides. Mirrors need to be full with water after each use to clean, stored in a dry ventilated place, and does not be exposed to direct sunlight. If you were in seawater using a mirror, it is best to soak in warm water for a few minutes to prevent the corrosive salt scale. If you are unable to use immediately after cleaning, Cheap Ray Bans are best face mask in the water, because the dried salt is difficult to completely remove.
|No 6 is not wearing sunglasses|
|Summer, sunglasses are one of the essential equipment travel, shopping. How can I identify glasses with UV feature? Kids out, you also need to wear Ray Ban Outlet sunglasses?|
Yesterday, reporters in chunks road in the large glasses shop, people buy sunglasses in an endless stream, even in individual glasses hold church started a fight. Regret is that lots of people buy sunglasses are not too good at it.
Blinkers ≠ sunglasses
Part of consumers believes that summer, wearing tinted glasses; both block UV rays and fashionable appearance. But professionals remind this is in fact a misunderstanding: jump is not equal to the sunglasses; wear no ultraviolet resistant functions through tinted glasses, more dangerous than not wearing! "Human instinct of self-protection, eyes, strong light, the pupil will become smaller, making eyes UV reducing once wearing no anti-UV spectacles, makes the pupils dilate, plus the glasses did not isolate the role of UV, eyes open and let UV intrusion, and greatly increased energy, damage to the eyes.” Professional advice, buy sunglasses the best regular glasses shop, select regular factory production with anti-UV sunglasses. Street-side stalls, hawkers sell glasses and often fail to meet the criteria for UV.
Frames not bigger is better
"When you buy Cheap Ray Ban Sunglasses, it is best to use slightly larger frames, spectacle frame slightly wider so that you can stand in the light reflected from the surrounding and selected spectacles frames sunglasses to cover eyebrows better.” Professional sales personnel told reporters, regardless of style or the fitness aspect, the big glasses are favored by the customers this year. But purchasing officers also stressed that "are not larger sunglasses frames better, frame oversize glasses are imported, are aliens according to face shape design, double pupil distance most of my adult large glasses of the optical center of the imports is less than the distance, wearing the glasses would significantly increase the burden of adjustment function of the eyeball, eyesight damage."
Lens color care
"Wear the colors of the surroundings after distortion, edge clear of objects, select lens color is in the past.” Professional, choose a Brown lens in myopic eyes are more comfortable hypertrophy better green lenses; grey lenses on any spectral balance absorption, is a more comprehensive lens, to clearly distinguish between colors after wearing, for everyone to wear. Dark green lenses absorb heat, brought cool feeling, but low light transmission and clarity, suitable for Sun wear, not while driving. Tinted lenses can block the smooth shiny surfaces reflect light, wearing glasses can still read all the details, is ideal for pilots.
Not under 6 mo sunglasses
Many mothers are going out for the baby is equipped with small sunglasses. In fact, children under 6 years of age it is best not to wear sunglasses. "The Visual function of children below the age of 6 is not yet mature, Cheap Ray Bans sunglasses wearing long, retinal oracular area cannot be effectively stimulated, will affect the further development of vision, even visually.” Professionals are alerted, glaucoma is not one of the crowd wearing sunglasses, because after wearing sunglasses, the patient is likely to appear with startling sharp decline in vision, eye pain, headache, and even nausea, vomiting and other symptoms.
|Pros and cons glasses simple testing method and described astigmatism lens|
To check the quality of Ray Ban Outlet
sunglasses, for ordinary consumers, there are several strong operational simple tests:
1, the test lens transparency and optical homogeneity: hand lens at front about 30 cm from the lens observe a far object, if the scene clear, no deformation, and moving slowly and no jump, then the transparency of the lens and the light uniformity were better.
2, the test optical center Displacement: fine strokes on white paper with a large cross, the stroke should be clear and straight. Handheld lens placed between the eye and the Cross, with an eye in the mirror the shape of the observed cross strokes, inside and outside mirror if the stroke is not a line, removable lenses, the lens inside the cross stroke of the cross with the outside mirror strokes in a line, then brush or fountain at the center point of the lens cross a small point, this point is the optical center. Two lenses are point out the optical center, the optical center is observed and compared with bilateral symmetry, and with a small ruler to measure the distance between the centers are two provisions of the pupil with the same distance prescription. If the lens of the cross strokes bend, then the existence of internal stress lenses or optical density in homogeneity problems.
3, the measured axial astigmatism lens: the lens in a cross pattern 30 cm above the rotation, showing the lens of the cross of cross movement, until the lens inside and outside of the cross strokes linked graphics, the graphics were positively cross, this time cylinder axis and straight line, then the lenses were repeatedly moved along a straight line, which was observed in a straight line and the lens moves straight out stagger more, this line is the astigmatic axis, move straight alignment of the lens so that the inside and outside, here astigmatic axis In Cheap Ray Ban Sunglasses
lenses superscript plans, then the amount of the solver is measured at the center of the lens axis and horizontal angles, namely axial degrees.
Astigmatism is not only bad eyesight, and is often accompanied by visual fatigue, headache, eye pain and other symptoms. Especially mixed astigmatism, is one of the important reasons causing headaches. So people, who have astigmatism, should be timely wear glasses.
In addition to high astigmatism can slightly reduce the degree of discretion, the general degree of astigmatism is best not to change, that is not at liberty to reduce the degree, in order to get the best corrected visual acuity and eliminate eye fatigue caused by the symptoms of astigmatism. If the two axial astigmatism optometry inconsistent results should be considered when there is an optometry inaccurate or insufficient scale audition shelf registration, to the best corrected visual acuity of a refraction results as the standard. A high degree of astigmatism or oblique axial shaft and anti-people, such as an eye astigmatism axis at 180 degrees, the other eye astigmatic axis was at 90 degrees, in this particular case with a mirror to it may cause visual distortion, was oblique, inclined or prone to depression, convex protrusion, or the wide side of the narrow side to see things, to see the ground and then there is a feeling of injustice and so on. When the above condition is not normal, the degree of astigmatism should be re-checked and axial.
If after checking degrees and astigmatism axis are correct, you need to be appropriate to reduce the degree of astigmatism. After checking again, though still mild dizziness, deformation, etc., but after wearing Cheap Ray Bans
sunglasses general adaptation period, the majority can be restored to normal. If there are special circumstances, prior to the prescription and the patient speak clearly so that patients have a mental preparation.
|Pay attention to protection of eyes watching TV|
|Watching television affect the eyes healthy? Such as the impact, how should we protect your eyes? Concerned has released results of a survey, the experts thus made four recommendations.|
By the Electronic Chamber of Commerce Consumer Electronic Product Investigation Office, digital TV standards compliance testing center and other units jointly released findings that: If a long time watching TV while not wearing Ray Ban Outlet, can cause varying degrees of visual fatigue and eye dryness. Compared with LCD TV, plasma TV visual fatigue caused by light, the eye is relatively comfortable.
Conference, deputy director of Physicians Hospital Tam Key Geisha test case:
32 test averages is divided into two groups, in the same environment, alternately watching both LCD and plasma TV for 3 hours. In a separate inspection of 3 indicators before and after watching, contrasting two TV trend in these indicators, namely concluded. These 3 indicators are: blink frequency (increased eye fatigue); tear secretion (filter paper whetted length reduction shows that reduction of tear secretion), tear film break time (time reduced to dry eyes). Tests concluded that after LCD TVs, increased frequency of blinking than the plasma TV 20%; to blink more, longer the tear film break; tear secretion of two TV there were no significant differences.
Well, after a long time watching television, do not wear Cheap Ray Ban Sunglasses. Eye fatigue why?
National Radio and Television Product Quality Supervision and Inspection Center, Professor Changchun explained TV visual fatigue affect two main factors: First, the brightness, the second is the color temperature.
From the brightness of view, plasma TV's brightness fit, while it works flickering television images of small decisions, when viewing the human eye will feel comfortable. The high brightness LCD TV looks clearer. However, the brighter the screen, the critical flicker frequency is higher, is not conducive to the human eye health. Look from the color temperature, color temperature is high, blue sky and sea on the performance of more vivid and so cool, the human eye irritation as well. Conversely, the lower the color temperature, the displayed color than normal, the human eye irritation is also smaller.
How to protect your eyes when watching TV? Changchun made four recommendations:
1. Watching TV, the eyes should be comfortable as a standard, not just high-brightness figure. High brightness is not conducive to eye health, but also easy to reduce the life of the display, but also more energy consumption; using LCD TV viewers, should pay attention to reduce the brightness. 2. Regardless of what kind of TV watching should pay attention to the color temperature down. Debugging TV color, it is best to moderator complexion as the standard, so good for the eyes. 3. Do not continuously watch TV more than two hours, more than two hours, you should let the eye rest 5-10 minutes. 4. Night watching TV, the best opening behind the TV or wearing small lamp Cheap Ray Bans sunglasses, this will help to reduce eye fatigue.
Experts also stressed that LCD and plasma TVs have two kinds of length of the field in the small screen, LCD price advantage; areas on the big screen, plasma cost advantage.
|Must know basic knowledge of glasses(3)|
|Frequently asked questions about glasses:|
What do coated lenses?
Is the Ray Ban Outlet of the lens surface and multilayer anti-reflection coating to reduce secular reflection, increase transparency, ensure visual clarity, increased sense of beauty, and reducing red, UV damage to the eyes.
When children with mirror should pay attention to what issues?
When children's glasses, lenses of General resins (light, security, harder), but the surface is easily scratched, so best to use hard film of Plexiglas. At the time of the selected frame, depending on the child's face, choose a suitable, safe, light, durable frame (generally high with plate-frame), and attention should be shoulder length, to increase the stability of frame, most children are restless, so is equipped with chains on, hanging around the neck.
Why measuring interplanetary distance when the glasses?
Purpose of measuring interplanetary distance are available so that the optical center of the lens and binocular papillary distance is consistent so patients wearing comfort, or a Prism effect will occur, patients appeared as fatigue, dizziness, nausea and other symptoms.
Near to wear Cheap Ray Ban Sunglasses, look far down, very troublesome, what's good?
Can wearing a pay double light glasses, main tablets can see far, and Xian facial molecular tablets and Visual near, but double light mirror from appearance Sang comparison funny, depending on far district and depending on near district has obviously of "beats" phenomenon, or enjoy gradient mirror, can on from far to near all distance objects are has clear, continuous of Visual, and peerless light mirror of "light jump" phenomenon.
Color mirror is all about?
Color mirror was added silver halide materials, decomposition under strong light stimulation for the silver and a halogen, glass coloring, after the light is weak, and combined into silver halide, the color lightens. The process is reversible.
Photo chronic lenses can be changed forever?
Because this process will lose some element of long-term, slow lens lighting color capacity reduction, color lenses should be replaced regularly, at least once every two years.
Select sunglasses what is the scientific method?
Select Cheap Ray Bans sunglasses in addition to reducing the amount of light in order to achieve the purpose of shading and outside of the beautiful, the most important thing is to prevent UV rays.
Ultraviolet radiation on human eye what harm?
Long-term excessive exposure to ultraviolet light may cause conjunctiva, corneal and retinal damage, and common UV eye: baptistery, recurrent corneal infections, cataracts, retinal degeneration.
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