Where is the optical center for near vision located in executive bifocals?

• A. Geometric center of the lens
• B. Seg line
• C. Top third of the lens
• D. Bottom edge of the segment

Answer: (B)

The optical center for near vision in executive bifocals is located at the seg line. This is because executive bifocals are designed with a wide reading area that allows for seamless transition between distance and near vision. The seg line represents the point where the distance portion of the lens transitions into the reading segment.

This design ensures that the optical center for near vision aligns directly with the user's line of sight while reading, promoting ease of use and reducing the need for repositioning when looking down at close tasks. Therefore, the optical center is strategically placed at the seg line to give optimal visual performance for tasks requiring near focus, such as reading.