Bifocals Design

Bifocals are dual-version glasses, you can see two different fields of vision through one pair of bifocal glasses. Bifocals are designed with two prescirptions on the lenses, so you can see far through the top part of the lenses, and reading book or use computer through the bottom part of the lenses.

What are bifocal glasses look like?

Bifocals Advantage

The designer designed the upper focal length of the lenses to be able to observe objects of more than 3 meters, while the lower part was designed to observe the close-up characters of the scene. This design enables the glasses wearer to observe distance/near different objects. It is not necessary to take off the glasses, which provides great convenience for presbyopia people.

Bifocals Disadvantage

Bifocal lenses are polished in far/near focal lengths. Due to the different curvatures of the lenses, two distinct parts are formed in the upper and lower parts of the lens. There is an obvious boundary between the upper and lower parts of the lens. The appearance is not good looking. During usage, when the line of sight moves from top to bottom or from bottom to top, the eyeball will constantly adjust, causing fatigue or dizziness.

If there is a high difference between the far and near degree, there will be an obvious “jump image”, which will cause dizziness and inability to judge the position of the high and low positions in certain scenes (such as stairs or walking) in different position of life.

Bifocals for the crowd

1. As the human eyes degrade with aging, the focal length becomes longer, and blurry images are observed for objects within a long distance, while objects within a short distance have little effect. This is the presbyopia. This phenomenon is common among middle-aged and elderly people over the age of 40.

2. Some type of occupational bifocals available for specific jobs. Tell your eye doctor if your need special glasses because of work. For example, golfers and car mechanics who need to see far and near, they may need bifocal glasses

3. If you like wearing contact lenses, bifocal contact lenses are also available.

How to identify whether you need a pair of bifocal glasses

Step 1
if you hold your newspaper or book at an arm's length in order to read it, you may need bifocals.

Step 2
Ask a friend to look if you are squinting while reading book or use mobile phone. If you are squinting, you may be presbyopia and you may need bifocal glasses.

Step 3
If you are in this age range between 40 to 60, your chances of developing presbyopia are high.

Step 4
Hold a book 0.3m from your face, then slowly move the book far away as you focus on the words on the book. If the words become clearer when the book is far away, you may need bifocal glasses.

Step 5
See an optometrist, he will determine if you need bifocals. And, he will provide a bifocal perscription for you.