Glasses:

Glasses are a special kind of health care supply. Everyone at some point in their lives will come in contact with a pair of glasses, whether it is to look afar or for reading. A pair of good glasses will not only achieve its functionality of optical correction, it could be clear, comfortable, and a fashion accessory.

Sunglasses:

Sunglasses nowadays are more of a fashion statement than protective gear. However, they play a crucial role in reducing the amount of sunlight that reaches your eyes and preventing ultraviolet (UV) light from damaging your eyes. Long-term excessive exposure to UV rays can lead to the conjunctiva, cornea, and retina damage. Common eye diseases associated with UV light include: pterygium, recurrent keratitis, cataracts, age-related macular degeneration, etc.

1. Ordinary Sunglasses: The primary function of most sunglasses are to block the sun. The dyed lenses reduce the intensity of the light, and effectively remove the shiny and reflective glare in all directions. In addition to sunlight and UV light, glare irregularly diffuses light, which are created by uneven pavement, water, and other sources. The discomfort and fatigue caused by glare could affect the clarity of vision and result in serious impact, especially for drivers. Ordinary sunglasses are a solution to that problem.

2. Transitional Sunglasses: Transitional Sunglasses are a type of sunglasses that changes color depending on strengthen of the light. Silver Halide is added to the lens, causing decomposition of silver and halogen in daylight and with ultraviolet stimulation. The silver in free form inside the lens will form small aggregates, and these small aggregates of silver become jagged irregular blocks, which cannot transmit light, but absorb light, which makes the lens colored. When light becomes weak, the blocks form silver halide, and the lens restores to being colorless and transparent. Although transitional sunglasses are in their seventh generation now, the long-term impact of this reversible reaction could cause the lens to lose some of the elements, and the changing of color slows with diminished capacity. Therefore, it is best to replace the transitional lenses regularly. Transitional Sunglasses are suitable for indoor and outdoor, and comes in shades of gray and brown.

3. Polarized Sunglasses: Polarized Sunglasses are suitable for driving, fishing, biking, hiking, mountaineering, and all sorts of outdoor sports. Here is how it works: Light reflected from surfaces such as a flat road or smooth water generally is horizontally polarized. This means that, instead of light being scattered in all directions in more usual ways, reflected light generally travels in a more horizontally oriented direction. This creates an annoying and sometimes dangerous intensity of light that we experience as glare. Polarized lenses contain a special filter that blocks this type of intense reflected light, reducing glare. Though polarized sunglasses improve comfort and visibility, you will encounter some instances when these lenses may not be advisable such as using them to see LCD / LED lights, read GPS or phones, etc. For outdoor sports enthusiastic, a pair of polarized sunglasses are surely a great investment.