Single Vision vs Bifocal vs Progressive Lenses Explained

Single vision lenses have one prescription across the whole lens, for either distance or reading. Bifocal lenses have two zones, usually distance on top and reading below, with a visible line. Progressive lenses change gradually from distance to middle to reading, with no line. Which you need depends on your prescription and how you use your eyes day to day.

Single vision lenses

Single vision lenses have the same power across the lens. They are used for:

• Distance: driving, TV, seeing across a room. Common for short-sightedness (myopia).
• Reading: books, phones and close work. Common for long-sightedness or age-related focus changes.
• Computer: some people have single vision lenses set for screen distance.

They give a wide, clear field of view and are easy to adapt to. The trade-off is that you may need more than one pair if you need help at different distances.

Bifocal lenses

Bifocals combine two prescriptions in one lens. The top part is for distance and a smaller segment at the bottom is for reading. There is a visible line between the two.

• Pros: wide reading area, quick to get used to, simple to understand.
• Cons: no clear middle distance (such as a computer screen), the line is visible, and the image can appear to "jump" when your eyes cross the line.

Progressive lenses

Progressive lenses (sometimes called multifocals or varifocals) have a smooth change in power from top to bottom:

1. The top is for distance.
2. The middle corridor is for intermediate distances such as a computer or car dashboard.
3. The lower part is for reading.

There is no visible line, so they look like single vision lenses. The sides of the lens have some soft blur, which is a normal part of the design. Quality and design vary, and wider corridors usually feel more natural.

Comparison table

Who needs what?

Many people need help with close focus from their 40s onwards. This is called presbyopia, a normal age-related change in the eye's ability to focus up close. On a prescription it shows as an ADD value. If your prescription includes an ADD, you may be a candidate for bifocals or progressives. Our guide to how to read your glasses prescription explains ADD and the other numbers.

Your optometrist is the right person to advise on which lens type suits your eyes. We can then help you choose frames and lenses that work with that advice. For general eye health information, the American Academy of Ophthalmology is a reliable source.

Adapting to progressive lenses

Most people adjust to progressives within a few days to a couple of weeks, though it varies. These tips help:

• Wear them full-time from the start rather than switching between pairs.
• Point your nose at what you want to see, turning your head rather than just your eyes.
• Look down through the lower part to read, and drop your chin slightly for stairs.
• Take care on steps and kerbs for the first few days.

Fit is especially important. If the frame sits too low, the reading zone moves. See how glasses should fit. Accurate measurements also matter, including pupillary distance and lens height, explained in how to read glasses size numbers. If you still struggle after two weeks, come back to us or see your optometrist.

One pair or two?

Some people prefer one pair of progressives for everything. Others keep single vision readers for long reading sessions and progressives for the rest of the day. There is no right answer. Think about how many hours you spend driving, at a screen and reading, and whether swapping pairs bothers you. You might also want prescription sunglasses for outdoors, which can be made in single vision or progressive lenses. Read UV protection and sunglasses in NZ for why that matters here.

Lens material and coatings can improve any lens type. Read lens materials and thickness and anti-reflective coating explained.

Bring your prescription to our Panmure store and we will help you choose the right lenses and frame. You can also ask about prescription updates or reglazing your current glasses.