The Price of Progressive Lens
On both sides of the lens of the progressive lens, some places are deformed, which makes the image blurred. In addition, it has a narrow field of view in the near and middle distances. The narrow focus point for a long time can easily make the eyes tired. It is suitable for the alternate vision of far, middle, and near. Under normal circumstances, the price of the progressive lens is different from the purchase merchant, region, brand, and quality, but the price of the progressive lens on the official website is between 30-85 US dollars. Of course, some products will be less than $30, or more than $85.
What are prism glasses?
What is a prism? A prism is a solid object with a cross-section along its entire length. If you cut across something, you'll come across a section that's been cut, and that's a cross-section. The upward section is a prism. If you have double vision, you can add a prism prescription to the lens to form prism glasses. It can help keep your eyes focused and greatly improve your vision. In most glasses, prisms are used primarily to change double vision and are useful for image correction. They can aid in position correction.
Pure Titanium Glasses Frame Brand - Perspicilla
Perspicilla is a company specializing in the business of myopia frames, pure titanium frames, optical shops, titanium glasses, and other products.It is a limited liability company and has professional design and production of different styles of 3D glasses.It is a professional product design company.The wonderful design team and professional production team hope to bring customers the most satisfactory products.In the production of the product, the brand adheres to the perfect integration of progressive technology and high-quality raw materials, so its single product not only has excellent quality, and comfort is done well.
Titanium alloys have low thermal elasticity
The thermal conductivity of titanium is about 1/4 of nickel, 1/5 of iron, 1/14 of aluminum, and the thermal conductivity of different titanium alloys is about 50% lower than that of titanium.
The elastic modulus of titanium alloy is about 1/2 that of steel, so its rigidity is poor and is easy to deform, and it is not suitable to make slender rods and thin wall parts. When cutting, the spring back of the processing surface is very large, about 2 ~ 3 times of stainless steel, resulting in severe friction, adhesion, and bonding wear of the knife surface.
The lifetime of contact lens
Traditional type: the replacement cycle is more than 3 months, not more than 1 year, that is, we say we abandon after one season, and we can abandon after half a year and a year.
Frequent-change type: the replacement cycle is more than 2 weeks, not more than 3 months, that is, we often say that we throw them after 1 month or two weeks.
Abandoned type: as a one-time use, common for the day use.
Contact lenses, like food, have an expiration date. For example, the shelf life of daily contact lenses is one day (after it is opened), and can not exceed this time. And the life span of a pair of glasses depends on how long you use them each day. Although different lens materials determine different wear times, we recommend that soft lenses should not be worn for more than 8 hours per day (do not wear soft contact lenses to sleep). Traditional contact lenses can be used for a long time, so the lens is easy to produce protein-lipid deposition, and then they are easy to cause eye surface inflammation and hypoxia reaction. If conditions permit, it is recommended to choose the frequent-change type and discard type, the shorter the cycle, the healthier.
How Do Bifocal Glasses Work?
After learning some basic information about bifocal lenses, you should know how the bifocal glasses work.
With a pair of bifocal glasses, it would be convenient since they combine all your vision needs into a pair of glasses and you do not need to switch two pairs of glasses frequently. Bifocal glasses are usually designed to for those people who are over the age of 40-45 that need additional help with their near vision due to the effects of presbyopia where the crystalline lens inside the eye naturally begins to lose its ability to focus on near objects.
If you work in the office, you may need a pair of bifocal glasses. The top distance vision in the top of the lens can be used for meetings or presentations and the near vision in the bottom of the lens can be used to look at the computer screen or at documents.
Different Types of Progressive Lenses
Premium progressive lenses are designed to provide a wider and smoother view. These lenses are highly customizable for your prescription, chosen frame and eye anatomy.
Premium progressive lenses can incorporate your dominant eye into the design and make transitioning between different prescriptions feel smoother as well. However, due to these features, premium progressive lenses are more expensive than traditional lenses.