Varifocal vs Bifocal Glasses

If your optician has told you that you need multifocal lenses. Glasses that correct your vision at more than one distance. The next question is usually: varifocal or bifocal?

Both lens types correct distance and near vision in a single pair of glasses. However, the difference between them is significant. The right choice depends on your lifestyle, your prescription strength and what you are most comfortable with.

This guide explains how each lens type works, where they differ, the pros and cons of each, and, most importantly, which type is likely to suit you best.

This page covers the choice between varifocal and bifocal lenses.

A bifocal lens has two distinct prescription zones, physically separated by a visible dividing line. The upper portion of the lens contains your distance prescription for driving, watching television or looking across a room. The lower portion contains your reading prescription for books, phones, menus and close-up tasks.

The line between the two zones is a real optical boundary, not simply a change in lens curvature. When you look through the main portion of the lens, you get distance. When your eyes drop below the line, can focus on nearby objects such as reading. There is no gradual transition between them.

Types of Bifocal Lens

The most common bifocal lens design in the UK is the flat-top or D-segment bifocal. Where the reading segment is a D-shaped area in the lower portion of the lens. The flat edge of the D is the visible line.

A less common variant is the round-segment bifocal. Where the reading area is a circular window within the lower lens. This is more visible but easier for some wearers to locate.

Executive or E-style bifocals, occasionally prescribed for occupational use. Where the line runs the full width of the lens.

At Direct Sight we only offer the D28 Bifocal Lens.

What Bifocal Lenses Do Not Provide

As Bifocal lenses have only two zones, they have no intermediate vision correction. They will not cover arms length distances such as, a computer screen, a car dashboard, a music stand, supermarket shelves. This gap in the middle is the fundamental limitation.

Varifocal lenses, also called progressive lenses, solve the intermediate gap. A varifocal lens has a gradual change in prescription from top to bottom.

The top of the lens is your full distance prescription. The bottom is your reading prescription. The middle, the corridor running down the centre of the lens, provides an intermediate prescription between the two.

The prescription changes gradually rather than jumping between fixed zones and there is no visible line, for smooth focus at any distance. To an observer, a varifocal lens looks identical to a single vision lens.

The trade-off is that the prescription cannot be uniform across the full width of the lens. The sides of a varifocal lens, where the prescription transitions most sharply, are less clear than the central corridor. This peripheral distortion is the distinctive feature that new varifocal wearers often struggle to adapt to. It does not exist in bifocal lenses.

Some wearers find the visible line is not an issue. It is simply a practical feature of how the lens divides the distinct optical powers. After a few days of wear, they stop noticing it.

For others, particularly those who are conscious of the visible line or who associate the line with older age. Find varifocal lenses are cosmetically a better option.

Most bifocal wearers adapt quickly. But some find it distracting where the prescription changes abruptly rather than gradually. Particularly in dynamic environments such as driving or descending stairs.

Screens have changed the way most adults use their vision. A typical computer or laptop screen sits at a distance of 50 to 70cm. Too close for the distance zone of a bifocal and too far away for the reading zone. Reading from a mobile phone or tablet at arm's length may present the same challenge.

Bifocal wearers often find themselves tilting their head back to use the reading segment or leaning forward towards the screen. Often removing their glasses altogether when using a computer. None of these are comfortable over a full working day.

Varifocal wearers in the same situation simply look through the intermediate corridor of the lens at the screen. Then drop their eyes slightly to read printed documents. No head movement or removing the glasses required.

This practical difference matters less for wearers whose daily life does not involve significant screen use. If you spend most of your day reading books and rarely use a computer. The intermediate zone that varifocals provide may not justify the longer adaptation period that varifocal lenses often take.

For drivers, both lens types cover the distance zone. The dashboard sits at intermediate distance better served by varifocals. Though many experienced bifocal wearers manage this through small head movements.

Varifocal glasses are the better choice for most people whose daily life involves a range of viewing distances. Particularly anyone who uses a screen regularly or drives alongside reading. They are a great option if you prefer to avoid the visible line of bifocals or want the convenience of one pair of glasses.

Varifocals are likely the better choice if you:

• Spend significant time at a computer, laptop or tablet each day
• Drive regularly, the intermediate zone covers dashboard distances that bifocals do not
• Want glasses that look like single vision lenses from the outside
• Have a prescription that includes significant astigmatism alongside your reading addition. Freeform varifocals handle complex prescriptions well across all zones
• Are ordering glasses for the first time and have no strong preference. Varifocals are now the default recommendation from most UK opticians to correct presbyopia
• Are active or outdoors frequently and need clear vision at multiple distances without thinking about which zone to use

Bifocal glasses are the better choice for wearers whose lifestyle naturally divides into two clear distances. Typically looking across a room and reading, without significant screen use or complex intermediate needs. They are also worth considering if a previous attempt at varifocals was unsuccessful.

Bifocals are likely the better choice if you:

• Have already tried varifocals and found the peripheral distortion or adaptation period too difficult
• Rarely use a computer or device screen, your daily vision is divided between distance and reading
• Have a strong preference for the simplicity of two clear zones rather than a graduated corridor
• Need glasses for a specific activity where two clear zones are more practical, eg. certain occupational tasks where distance and near are alternated in a regular pattern
• Want a wider choice of frames, bifocal lenses require less vertical depth and are compatible with more frame styles

Switching from bifocals to varifocals

Moving from bifocals to varifocals requires a genuine adaptation period, typically one to two weeks of consistent daily wear. The key challenge is learning to use a graduated corridor rather than jumping between two fixed zones. Learning to ignore peripheral distortion that did not exist in your bifocal lenses.

Wearers who have worn bifocals for many years sometimes find this harder than first-time varifocal wearers. With varifocals, you move your head rather than your eyes to focus through the centre of the lens.

The most common mistake is expecting the reading zone to be where the bifocal reading segment was. In a varifocal, the reading zone is at the bottom of the central corridor. This is accessed by lowering the eyes further than bifocal wearers are used to. Our adjustment guide covers this in detail.

Office lenses (occupational progressives)

An office lens is a specialist lens designed for desk and screen use. This is sometimes called a near-variable focus or occupational progressive.

It covers near and intermediate distances (from reading distance up to approximately two metres). It has a wider, more comfortable near corridor than a standard varifocal.

Office lenses do not include a distance prescription and cannot be used for driving. They suit wearers who spend most of their working day at a desk. Direct Sight offers the Office Lens as one of its four varifocal options.

Separate pairs for distance and reading

For some wearers, particularly those with straightforward prescriptions opt for two separate single vision pairs. One for distance and one for reading.

Single vision lenses eliminate both the adaptation period and the peripheral distortion of varifocal lenses entirely. They are often a more cost effective option. The inconvenience of switching between two pairs is the only drawback.