How to choose suitable prescription glasses?

An unsuitable pair of prescription glasses will not only fail to correct the effect of the vision but will also aggravate the vision loss and cause serious headaches, dizziness, and nausea. So, how to choose the right eyeglasses products?
First, how to purchase a suitable pair of prescription glasses?
First, you need to go to a regular hospital or clinic for optometry. When you get the prescription list, you can pick the right eyeglass frames and lenses according to your face shape, parameters, and price. The merchant will follow the parameters and requirements of the prescription list for processing and production, and the completed prescription glasses should meet the requirements of the national standards.
After the glasses are made, appropriate adjustments are made to make the glasses comfortable to wear as well as beautiful. Generally speaking, if the parameters are appropriate when wearing the new glasses, it will feel very clear.
Second, how to choose eyeglass frames?
In the choice of an eyeglass frame, in addition to the price, beautiful as the standard, pay special attention to the selected frame size and my pupil distance as far as possible to match because this choice directly affects the inner optical quality of the glasses and wearing comfort. Identification of the quality of the frame can mainly consider the following: 
1. good elasticity of the frame is generally better quality.
2. The quality of the frame with a smooth and shiny coating is better.
3. Weld smooth, small, and uniform frame quality is better.
4. The parts assembled closely is good.
5. The size and shape of the left and right rims must be exactly the same, and the nose bridge symmetry.

6. Some common natural material eyeglass frames such as horn rimmed glasses are now also artificial materials, and need to be carefully identified when choosing.
Three, how to choose eyeglass prescription lenses?
Generally speaking, eyeglass lenses can be divided into two categories, namely glass lenses and optical resin lenses.
Glass lenses include optical glass lenses and high refractive index lenses (commonly known as ultra-thin lenses); their high hardness and good wear resistance, generally its quality and parameters will not change over time, but the impact resistance of glass lenses and weight is slightly inferior to resin lenses.
Resin lenses are generally much lighter than glass lenses and have better impact resistance than glass lenses, but their surface hardness is lower, and they are more easily scratched. Resin lenses and coated lenses because of their soft characteristics, so usually should be careful not to let the mirror surface make direct contact with hard objects; scrubbing is best first cleaned with water (or mixed with a small amount of detergent) and then with a special test cloth or high-quality cotton paper to absorb the water droplets on the glasses lens. In addition, in poor environmental conditions should be careful with coated lenses so as not to stain the dirt and make it difficult to clean.
Fourth, the glasses after-sales.
Consumers encounter the quality of glasses, one is the top focus degree (commonly known as degrees) is not allowed, that is, the top focus degree of glasses and the wearer needs to correct the diopter is not consistent; two is the pupil distance is not allowed, that is, the optical center of the glasses horizontal distance and the wearer’s pupil distance does not match; three is the column lens axis deviation does not meet the product standards. These inconsistencies have a direct impact on the correction effect, causing visual fatigue of the wearer, thus aggravating vision loss, which can seriously cause headaches, dizziness, and nausea. Consumers the glasses before should first use optometry, not blindly buy.