Peripheral Vision Training for Reading: What Really Works

Peripheral vision training for reading rests on an attractive idea: if you could see more words on either side of the point you are looking at, you would need fewer eye stops per line and would read faster. The first half of that idea does not hold up. The amount of text you use in one glance is limited mostly by attention and by how quickly you process language, and only partly by the sharpness of your side vision. Practice can make you better at noticing things away from your point of gaze, but it does not turn the edges of your vision into a second reading area.

That still leaves something worth practising, as long as you know what it is. This guide explains the three zones of vision, what the research says about the reading span, what training has been shown to change, and how to use two short drills sensibly.

Foveal, parafoveal and peripheral vision: what is the difference?

Your sight is not equally sharp across the visual field. In his 2009 review of eye-movement research, Keith Rayner divides the line of text you are reading into three regions, measured in degrees of visual angle from the point you are looking at.

This falling-off in sharpness is the reason your eyes move at all. You shift them several times a second so that the fovea lands on whatever you want to see clearly, as described in how your eyes move when you read. What people call peripheral vision in speed reading is, strictly, mostly parafoveal vision: the few degrees just to the side of where you are looking.

What is the perceptual span, and can you widen it?

The perceptual span is the stretch of text you get useful information from during a single fixation. For skilled readers of English it runs from about 3 to 4 letters to the left of the fixation point to about 14 or 15 letters to the right. Words are actually identified only in the nearer part of that window; further out you pick up word lengths and letter shapes that help you plan the next jump.

Researchers measure the span by changing the text as a person reads, so that only a window around the point of gaze is legible. The results show how little readers depend on anything further away. When only the word being fixated and the next word are legible, readers do not notice that the rest of the line has been scrambled and their speed drops by only about ten per cent; with two words to the right visible, there is very little slowdown at all.

Why the limit is attention, not eyesight

Several findings point the same way:

• Magnifying the side text does not help.Miellet, O'Donnell and Sereno (2009) enlarged letters progressively with distance from the point of gaze, to cancel out the loss of sharpness. Readers still took in about 14 letters to the right, the same as with normal text.
• The span follows the direction of reading. It is larger on the right for English and larger on the left for Hebrew, which is read from right to left. The eye is the same; what differs is where attention is sent.
• The span shrinks when the current word is hard. If the word you are looking at is difficult, you get little or no preview of the next one. Beginning readers and readers with dyslexia have smaller spans than skilled adults, and the usual explanation is that decoding the fixated word uses up the attention that would otherwise spread ahead.
• Faster readers have larger spans. Rayner, Slattery and Bélanger (2010) found a larger span in readers averaging about 330 words per minute than in readers averaging about 200.

The last finding is often quoted as proof that widening the span makes you fast. Taken with the others, it more plausibly runs the other way: people who recognise words easily have attention to spare for the text ahead.

The reading span is not a muscle and not a fixed property of the eye. It is the reach of your attention while you process a word, and it widens as word recognition gets easier.

What can peripheral vision training realistically change?

Training off-centre vision does something. Chung, Legge and Cheung (2004) had 18 normally sighted adults practise recognising letters shown 10 degrees above or below the point of gaze over four days. The range of letters they could identify there grew, and their maximum reading speed at that location rose by 41 per cent, a gain that largely held three months later.

Read that result carefully, though. It concerns reading with peripheral vision only, text shown one word at a time 10 degrees from the fovea, which matters to people who have lost central vision. It does not show that ordinary reading, done with a healthy fovea, gets faster. We found no controlled study showing that peripheral drills raise normal reading speed, and the review of speed reading by Rayner and colleagues (2016) concludes that speed is limited mainly by language skill, with eye movements taking up only a small share of reading time.

So a fair expectation looks like this:

• Likely: you get quicker and more accurate at the drill, and at similar tasks of spotting letters or digits away from your point of gaze.
• Plausible: you become more comfortable holding your eyes still and spreading attention, which some people find helps when reading several words per glance. See chunking for that technique and its limits.
• Unlikely: reading whole lines in one fixation, reading down the middle of a page, or a large jump in words per minute with the same understanding.
• Not possible: enlarging your visual field or restoring side vision lost to an eye condition.

What does widen the span is becoming a more fluent reader: wider vocabulary, more reading, more familiarity with the subject. How to read faster covers those, and does speed reading work? reviews the evidence.

How to practise with the Peripheral Letters and Schulte drills

Two of Tachi's drills ask you to notice items away from the point you are looking at. Treat them as short attention exercises, three to four minutes in total.

In Peripheral Letters, a centre mark appears, then one, two or three letters flash for 250 milliseconds at random positions around it, in up to eight directions. That is about the length of one reading fixation, short enough that looking across at one letter costs you the others. On a typical screen the letters sit a few degrees from the centre, so this is parafoveal practice, the zone that matters for reading.

1. Sit at your normal reading distance and keep that distance from day to day, so your scores are comparable.
2. Start with one letter and ten rounds. Stare at the centre mark and do not chase.
3. When you get at least 9 of 10 right, move to two letters; when you reach about 80 per cent with two, move to three.
4. Do one set of ten rounds, about two minutes. If your score falls on a second set, that is tiredness; stop.

The Schulte table is the slower, self-paced counterpart: nothing flashes, so the discipline of holding your eyes on the centre is entirely yours. Do two or three 4×4 grids, moving to 5×5 when 4×4 feels easy, and then go and read. A simple weekly pattern is both drills on five days, followed each time by at least five minutes of real text. The complete routine is on the How Tachi works page.

Safety: when to see an optometrist instead

These drills are attention practice for people with healthy eyes. They are not vision therapy and they do not treat anything. The American Academy of Ophthalmology states that eye exercises do not correct short-sightedness, long-sightedness or astigmatism and will not remove the need for glasses.

Real loss of side vision is a medical matter. Glaucoma, for example, usually has no early symptoms and then slowly takes peripheral vision first, so gradually that many people do not notice. No exercise reverses that. Book an eye examination if you find you are missing things at the edges of your vision, bumping into objects, or seeing blind spots, and seek urgent care if your vision changes suddenly. If the drills themselves give you headaches, eye strain or dizziness, stop, and mention it at your next eye test.