Is the Height of a Bifocal Height?

by Oct 24, 2023

When it comes to ordering bifocal glasses or progressive addition lenses, one crucial measurement that often goes unnoticed is the segment height. This measurement determines the placement of the bifocal or progressive segment in the lenses and plays a vital role in providing clear and comfortable vision. It may seem like a minor detail, but getting the segment height right can make a world of difference in how well your glasses perform. In this blog, we will explore why segment height matters for bifocal and progressive glasses and why it’s essential to have it accurately measured and specified in your order.


The Role of Bifocal Height

The segment height refers to the vertical distance between the bottom edge of the lens and the top edge of the bifocal or progressive segment. This measurement is crucial because it determines the location of the segment on the lens, ensuring that it aligns correctly with your eyes’ natural focus points. The goal is to find the sweet spot where the segment provides optimal vision correction for both distant and near objects.


Impact of Incorrect Segment Height

Bifocal Height Too High

If the segment height is set too high, it can lead to visual distortions and blurriness when looking at objects in the distance. The main issue with a high segment height is that it causes the bifocal or progressive segment to interfere with your distance vision, affecting your ability to see clearly in the distance. This can be particularly problematic if you spend a significant amount of time focusing on distant objects, such as driving or watching TV.

Segment Height Too Low

On the other hand, if the segment height is too low, it may cause difficulties when reading or performing close-up tasks. In such cases, you might find yourself constantly lifting or tilting your head back to look through the lower part of the lens where the segment is located. This can be inconvenient and uncomfortable, especially if you engage in activities requiring prolonged near vision, such as reading, working on a computer, or doing intricate tasks like sewing or crafting.


The Importance of Accurate Measurement

Given the potential problems associated with incorrect segment height, it is crucial to have this measurement accurately assessed and specified by an experienced optician. When you visit an optician to order bifocal or progressive glasses, they will measure your segment height as part of the fitting process. This is typically done while you are wearing the frame that you have selected for your glasses. During the measurement, the optician will consider factors such as your pupillary distance, the placement of your eyes within the frame, and your specific vision needs to determine the optimal segment height for your lenses.


Writing the Segment Height into Your Order

Once the segment height has been measured, it is essential to ensure that it is clearly indicated and written into your eyewear order. This step helps to eliminate any ambiguity or confusion during the lens manufacturing process, ensuring that your glasses are crafted precisely as measured. By specifying the segment height on your order, you can have peace of mind knowing that your glasses will be customized to provide the best possible vision correction.


Seeking Professional Guidance

When it comes to vision correction, it is always best to seek the expertise of a qualified optician or care professional. They have the knowledge and tools to measure and determine the appropriate segment height for your bifocal or progressive lenses. Additionally, they can guide you in selecting the right frame design and lens options based on your lifestyle and visual demands.


Our eye doctors at Neal Eye Group in Conshohocken, PA excel in prescribing contact lenses, glasses and various eye diseases. Call our optometrists at (610) 828-9701 or schedule an appointment online if you would like to learn more about segment height for glasses. Our optometrists provide the highest quality optometry services and eye exams in Conshohocken, Norristown, Plymouth Meeting, Lafayette Hill, and Philadelphia.

Request Appointment

You can schedule your next appointment with us online!

Connect With Us

Let’s continue the conversation over on your social network of choice.