The first glasses that were invented were really different from the ones we have now. The first ones were invented around 1000AD by the Greeks, they were called reading stones; they were a glass sphere that was laid on top of the reading material to magnify the letters. Alessandro Della of Spin, was the first person who revolutionate the look of glasses. He came up with the idea of making 2 cristal stones, and to put 2 iron thics within them so humans could hold them with their hands, since then the glases have been revolutionazing the ones we now have.
Glasses are very important to all people who have problems with their vision. Glasses are very helpful to get a better vision, in some cases they help to look far, or to look near, it depends on the problem that each person has.
The lens has a line through the optical center of the eye that helps to clear the secondary axes of sight of a person
In your vision exists focal distances; which are the distances between the main focus and the optical center, this reflects the parallel rays from a point until it reaches a good vision which helps it differentiate what the person is looking at. It is also important on how glasses are made now compare to years back. The technology has improved. For instance, it is now possible to purchase frames made of special memory metal. This allows the glasses to return to their correct shape after being bent. We now have contact lenses. Even though contact lenses became very popular, eyeglasses remain very common as both of their technology has improved. Now frames are very important. They have the ability to withstand the stress of daily wear and the occasional accident. Modern frames are now made from titanium, which were not available in the early years. These three are basic eyeglasses correctives that have help millions of people around the world are. First the Corrective lenses. Corrective lenses are used to correct refraction errors. This is an error in the focusing of light by the eye. A special lens was created for this purpose. Second Concave lenses. Is a lens that help vision disorder called Myopia. This causes far objects to appear blurred but near objects are seen clearly. Individuals suffering from myopia are prescribed eyeglasses with Concave lenses. Third are the Bifocals. These are lenses that help with a condition called Presbyopia. This is a condition where the eye exhibits a progressively diminished ability to focus on near objects with age.
They also developed a very important type of glasses. They are called Safety glasses. These glasses are usually made with shatter-resistance plastic lenses to protect the eye from flying debris. This invention has saved many eye accidents and has saved many eye injuries. It is also used in the medical field. For example, those used in medicine may be expected to protect against blood splatter while safety glasses in a factory