What are bifocals?
A bifocal lens is a lens with two focal points. Because of the imaging principle of the lens, even half of the lens can still present a complete image, and the two images do not interfere with each other. In the past, both short-sighted glasses and presbyopia glasses were called single-focal lenses, which had only one focus. Later it developed to the bifocal lens, and the same lens is divided into upper and lower two parts. The upper part of that lens is used when seeing far, and you look down when seeing close objects, just the reading distance, naturally used the second half.
Glasses Size - Frame Width
To really know how big a frame is, and how it will look on your face, you have to determine the width of the entire frame. The outer width of the frame is the distance between the visible areas on the left and right sides of the frame, namely, the distance between the frame and the junction of the two temples. The inner width of the frame is the distance between the inner sides of the two temples at 60mm behind the plane of the lens. This is just the contact point between the temple and the human temple. If it is too tight or too loose, it will affect the wearing comfort. The weight of the frame is evenly distributed across the bridge of the nose (or evenly distributed between the two nose pads on the bridge of the nose).
Eyeglass World
Eyeglass World has in-store LABS in every location, so most prescriptions are available on the same day. If you are looking for upgraded lenses, finished sunglasses, or other special lenses, Eyeglass World can handle these special options at home and get them back to you the same day! Many optical locations do not provide such quick service.
Different Types of Progressive Lenses
The first progressive lenses we want to introduce are computer progressive lenses, which are designed for clear vision in office settings. These lenses are ideal when using a computer for over 4 hours a day and help to reduce eye strain.
Computer progressive lenses are intended for indoor use and should not be worn over your regular glasses. The drawback to this is it requires you to have two separate pairs of eyeglasses.
Discoloration time and fading time for color-changing lenses
In general, color-changing lenses take about 30 seconds to 1 minute to darken on average when exposed to sunlight/UV and will continue to darken for about 10 minutes to reach the lens depth of full-color sunglasses. Color-changing lenses of good quality and workmanship are restored to an almost clear and transparent state in 2 minutes and completely cleared in 5 minutes, although the high temperature can affect this. If you want to change a single color change lens, the color of the old and new lenses will be inconsistent. This is because the discoloration performance of the old lens will be reduced due to the long-term use of the discoloration agent. Therefore, in order to ensure the normal use and aesthetic appearance, it is usually recommended to replace the two lenses at the same time.
The Optical Center of A Lens
When wearing glasses, try to look through the optical center of the lens. This needs the cooperation of the neck, you can slightly lower the head when looking at the computer, to adjust the line of sight. The Center of optical glasses is divided into two kinds: 1 mm up myopic lens center is the most proper, of course, more than 2-3. And the most important thing is that the lens pupil high (about the two-lens optical center of the high and low) must be proper (that is, the right of the lens optical center is 1 mm, the left must be 1 mm. 2-3 mm is the same, what is the height of the pupil on the right side must be the same on the left side. The optical center of the presbyopic lens is 1 mm, the most proper.
Joanie
Wrapped in a rich, multicolored opaque pattern in creamy pale pink, Joanie Reading Glasses features a square frame that is a statement of personality. As part of Foster Grant's Modera series, these frames give your makeup just the right amount of color and gloss. The spring-hinged temple provides a comfortable feel suitable for all-day wear.
