Important to measure pupils
The interpupillary distance refers to the distance between the centers of the two pupils when the visual axis is square and parallel. In general, the optical center of the glasses should coincide with the visual axis of the eye when looking at eye level. That is, the optical center distance of the glasses should be the same as the interpupillary distance. Otherwise, visual discomfort will occur, causing visual fatigue and deepening the degree. Therefore, we must improve consumers' awareness of self-quality protection. Understand the knowledge of glasses, otherwise, only mild myopia, the long-term wearing of unqualified glasses will cause the degree to deepen and become high myopia. So be sure to go to a regular optician to get glasses.
Choose a good merchant.
The best option is to return the goods with a quality guarantee.High-quality pure titanium frame production cost is not less than 100 yuan, and online sales will be not less than 50%, so you have to be careful with prices less than 200 yuan. Because pure titanium frame material cost determines its price, the ultra-low price of pure titanium frame is definitely not real.
The Disadvantages of Glasses Without Prescription
In this section, we will list some of the disadvantages of glasses without prescription. Even if you are a good candidate for non-prescription glasses, professional advice is recommended. It is not recommended to buy higher values without medical advice. If you need a different correction for each eye or have astigmatism, prescription lenses are more suitable.
Types of Progressive Lenses
At the same time, there are different types of progressive lenses and they are standard PALs, short corridor PALs, computer PALs, and Reading PALs.
Standard PALs must fit your vision needs. They can be added to frames of your choice, but you need to ensure that the frames are the right width and height proportions to grant enough space for the gradient changes in the lens.
Short corridor PALs are made to fit into smaller frames so as to suit a wider range of eyewear styles.
Computer PALs are designed for computer users and other occupations that require strong intermediate and distance vision.
Reading PALs are designed for those who enjoy reading and they can opt for a pair of lenses with a larger close vision zone.
Choose a quality progressive lens.
Superior progressive lenses provide a better viewing experience. They also remove any distortions you might feel when reading what's in front of you. Lenses can also be coated with special coatings. Anti-reflective coating can prevent glare on the road, and anti-scratch coating can reduce wear marks.
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.
The lens coated with anti-reflection film is pretty prone to stain, and the stain will affect the transmittance of the lens. Microscopically, the anti-reflection film shows a porous structure, therefore, the oil is very easy to soak in it. The solution is to coat a layer of anti-fouling film with anti-oil performance on anti-reflection film. The film is very thin and will not change the optical performance of the anti-fouling film. The material is mainly fluoride. There are two processes, one is the immersion method, one is the vacuum coating method (the most commonly used).