It is said, "Health is wealth". Is it true? Yes surely it is true because weakness of any thing is not appealed by anyone. The reason behind this is that in order to get rid of the weakness, sometimes handsome money is required to cure the weakness. People usually agree to spend for the cure of weakness as there is no alternate way. Eyes are the beautiful gift from God to mankind. If the eye sight weakens, the problem rises in terms of education, working and in many aspects. Thanks to modern science for developing contact lens and optical glass for mankind.
It is the invention made earlier than that of contact lens. People with short and long eye sight weakness use contact lens and optical glass which may suite them best. Before the advent of lens, people often wear optical glass but now a day's people wear contacts to make the eyes perfect. Some merits and demerits of contact lens and optical glass must be discussed:
Merits of optical Glass.
1. It is easy to wear.
2. It needs no chemical solution to clean the glass.
3. Variety of photo-changing colors can be available.
4. Different designs in frames are available to get the glass fit in it.
5. Dust particles are not able to flow into eyes easily.
Merits of contact lens.
1. It is rather difficult to use than optical glass.
2. It helps to boost the personality.
3. A wide range of colors are available to wear accordingly as desired.
4. No need for any frame. But container is given along with the lens to place them after use.
5. While working in humid condition lens is the paramount to use.
Some disadvantages of optical glass and contact lens.
Disadvantage of optical glass.
1. It may inconsiderate the personality.
2. If a glass of complex number is broken, it may take time in manufacturing.
3. Some spots may be present on nose or around ear due to abundant use of the frame.
Disadvantage of contact lens.
1. Hard contact lens may irritate eyes and may give woozy vision.
2. Dust may directly reside on the lens.
3. A chemical solution is required to protect the lens after use.
Optical glasses are available in various frame designs and also in various photo sun glasses. There are usually three common types of color in optical glass.
1. Photo brown sun glass.
2. Photo black sun glass.
3. Plain sun glass.
These photo sun glasses change the color of glass with the intensity of sunlight. Qualities are available in such photo color glasses. Best quality must be selected to make sure the best result with long life.
Contact lenses are available in wide range than that of optical glass.
1. Hard contact lens have non flexible material with number of demerits
2. Daily disposal lens are used for a day and require no cleaning.
3. Silicone wear lens are less irritating and another type of contact lens.
Polycarbonate and Plastic are less expensive material for optic option while contact lenses are often expensive.
| Do visit Irsan's latest website at http://www.portablekeroseneheater.org which contains reviews and deals on Portable Kerosene Heater and other information about electric heaters. |
