What Are Bifocal Glasses?
Vision changes seem to be related to age. Presbyopia occurs in the middle age of one person, affecting your eye’s ability to focus. But it can be caused by bifocal glasses.
Bifocal glasses are divided into two parts to accommodate two different prescriptions in one lens. One area of the lens will have one prescription (usually distance) and a segment in the lower half will have the other (usually near vision).
Bifocal glasses were invented by Benjamin Franklin, who solved his own vision problem by taking the lens from his reading glasses and distance glasses and cutting them in half. Then remade the cut lenses into a single pair of bifocals and put the distance lens on top and the reading lens on the bottom.
However, the bifocal glasses come with some problems. So, in the following section, we will show you some common bifocal glasses problems.
Why are titanium glasses so expensive?
Pure titanium can guide the electron wave to produce ions so that the current tends to ionize, and positive and negative ions can reduce the harmful effects of the body's biological current chaos caused by electromagnetic waves. To the human body, it has a great health care role. It avoids fatigue, muscle stiffness, soreness, and other symptoms or problems.
3 Common Problems with Progressive Lenses
Though progressive lenses are popular to correct some eye conditions, there are also some drawbacks. So, in the following section, we will show you some common problems with progressive lenses.
Dizziness: the three different focal lengths of progressive lenses can make people susceptible to dizziness, as well as vertigo. From long to medium to short distance, the lenses offer a gradient of increasing strength. So, it would have trouble in adapting the glasses for the people who are wearing them for the first time. A common mistake is to look out of the wrong focal length, causing their vision to be blurry and lead to an overall feeling of dizziness.
Peripheral distortion: another common problem of progressive lenses is the way in which they blur peripheral vision. Most glasses cause an initial distortion to vision. However, the three different segments found in these lenses can make that distortion feel more prominent than other pairs of eyeglasses. And most people may need two weeks to adjust to progressive lenses.
Depth perception: Since progressive lenses provide three different prescriptions to see objects clearly for different distances, it is important that you need to move your head instead of your eyes when focusing on objects at different distances. Prior to adjusting to this little nuance, progressive lenses can cause depth perception to feel off.
From the above information, you have known some common problems with progressive lenses. So, you may ask how to adjust the progressive lenses. The most popular way is that you need to wear them frequently.
Why do people like wearing rimless glasses?
The simple atmosphere and extreme minimalism can highlight the characteristics of the character. They belong to the business type glasses. They are suitable for professors, principals, and other leaders. A minimalist style will keep them from going wrong in the work environment. Secondly, they can highlight professional temperament. Because rimless glasses style is more diverse, and stylish, with a rich color difference, they are popular for many people.
Discountglasses.com
Discountglasses.com once advertised a free try before you buy home audition kit for RX contact lenses, and the companies will send you two pairs already fitted with your own prescription lenses.Discountglasses.com now provides a virtual try-on program. Discountglasses.com provides free returns. You can safely order glasses to try on at home. The frames come with standard, high-quality 1.49 plastic lenses with a protective coating that protects the lenses from scratches and are prescribed between +/ -3.00.
How to Find Reading Glasses Strengths?
With the increase of age, your vision may begin to decrease and this is an inevitable change in your life. So, when you are trying to decipher some smaller prints, you may need the reading glasses.
When your vision begins to decrease, do not worry, this is a normal change. You will find that the deterioration insight often occurs around the age of 40. The technical term for this condition is called presbyopia, a natural, age-related change in the lens of the eye which makes it more difficult to focus on smaller print and close-up objects.
The condition may become worse as you are near 60 years of age, depending on the type of near distance tasks you performing. Of course, you also need to consider the actual situations.
Design principle of aspheric lens
Early optical lenses use spherical lenses. Because the glasses were small round frames, the problem of lens edge aberration was not paid attention to. It wasn't until large frames became popular that the problem became apparent. For the spherical lenses, aberration cannot be corrected with the combined lens. Only a few variables of the lens can be found to reduce aberration and improve clarity. Aspheric lenses are designed to reduce the aberration of optical correction lenses and to make lenses flatter and reduce lens magnification. We can get clearer, thinner, lighter-quality lenses. Thus, aspheric lenses are used to reduce aberration and astigmatism to a minimum, close to the natural vision of the naked eye. The spherical aberration can be reduced by changing the curvature of the edge. The refraction in the central region is high and decreases evenly toward the edges.
