What's the difference between bifocals, trifocals, and progressive lenses?

Q. How do I choose between bifocals, trifocals, and progressive lenses?

A. It mainly depends on your vision needs. The primary difference between these types of eyeglass lenses is how many vision "zones" they include and whether visible lines separate these zones.

As their name implies, bifocals have two vision zones, which are divided by a visible line. The top zone improves distance vision - for driving or TV viewing, for example - while the bottom one enables close-up tasks such as reading or phone use. Bifocals are ideal for people who mainly need help with distance and reading vision, but not much in between.

Trifocals include three vision zones separated by two visible lines. The top is for distance, the middle for intermediate tasks such as computer use, and the bottom for reading. Trifocals work best for people who otherwise couldn't see well at those three distinct distances.

Progressive lenses don't have any visible lines, but allow wearers to gradually shift from distance to intermediate to close-up vision help. People who want a more traditional look to their lenses tend to choose progressives, but they can be pricey and harder to adapt to.

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