Teaching Magnifiers For Reading

Magnifiers or large print Which magnifier?
Teaching reading with a magnifier Increasing reading speeds

Magnifiers or large print

Visiting (itinerant) teachers have all observed huge variation between
skills of vision impaired students who use magnifiers. There are many non-users,
some refusers, those who use them for reading labels and diagrams only and
some who read everything with them. I knew one senior student who “wore”
his magnifier in his eye socket and used it to read everything!

So, why should students use magnifiers?

Disadvantages for users of large print

  • enlarging can emphasise the imperfections in print
  • pictures are in black & white (and shades of grey)
  • labels on graphics or maths symbols may need further enlargement
  • large print books are very bulky, especially textbooks

Advantages for users of large print

  • little or no instruction is needed to use LP
  • a Low Vision Clinic evaluation is not required for LP
  • student may be less self-conscious when reading LP (doesn’t need
    to use any special aids)
  • LP books are funded by the production agency, whereas parental or other
    funding is required for magnifiers

Disadvantages for users of magnifiers

  • magnifiers should be prescribed by Optometrist
  • magnifiers and clinical appointments are usually funded by parents
  • the cosmetics of magnifiers may cause self-consciousness
  • optical problems associated with the optics of magnifiers
    need to be tolerated
  • instruction is required in use of magnifier
  • some time and commitment is required if student is to
    attain skill
  • reading speed and comprehension will probably be reduced
    in early stages of use

Advantages of magnifiers

  • magnifiers allow immediate access to print anywhere
  • maps and graphics can be viewed in true colours
  • lower overall cost per child than LP
  • lighter and more portable than LP
  • no ordering and waiting time for materials
  • may be more cosmetically desirable than using huge books
  • allow greater independence (and choice in reading materials!)
  • can be used post school

I believe these last two points make the teaching of efficient magnifier
use essential for many of our students. Magnifiers offer our students
more independence and options for literacy at and after school.

What does research tell us about the efficiency of using magnifiers or large

  • no significant difference in reading rates and comprehension
    found between individuals using large print and those using regular
    print with magnifiers (Corn, 1990)
  • another study did find that reading speed declined
    with greater magnification
  • shorter saccades lead to an increased number of fixations
    and slower reading speeds (Fotinakis & Dickinson, 1994)
  • students with retinitis pigmentosa achieve better reading
    speeds when using cylindrical mirror magnifiers (with only vertical
    magnification) (Spitzberg, Goodrich & Perez-Franco, 1994)
  • particular eye movements adopted by readers using magnifiers
    have greater influence on both speed and comprehension (Fotinakis &
    Dickinson, 1994)
  • implications for teaching effective technique (Fotinakis
    & Dickinson, 1994)
  • yet another study found that students who used magnifiers
    were more likely to progress beyond a ‘year 8’ reading level
    than those who used LP (Corn, 1990) This may be because the type of
    students who adapt to magnifier use are more likely to be brighter or
    more diligent students.

Which magnifier?

For students with vision impairments, magnifiers should ALWAYS be prescribed
by an optometrist as there are many optical considerations to be assessed
to optimise the student’s visual functioning. If a magnification
device is prescribed for your student, there are a number of details which
need to be asked of the optometrist.

These include:

  • what is the intended purpose for the aid? – for reading books, labels,
    textbooks, just for maths, dictionary, telephone books, etc.
  • what is its focal distance? (Distance from magnifier to page – see focal
    distance table.) – this is a fixed distance for stand or bar magnifiers.
  • at what distance should the aid be held from the eye?
  • should it be used with or without spectacles?
  • is it intended as a monocular or binocular aid?
  • should the student have one eye closed or both eyes open? (For young students,
    the muscular strain of closing one eye can cause distortion in the open
    eye which may not be desirable. It may be preferable to leave both eyes
    open even while looking through a monocular aid.
  • with which eye should the student use the aid?
  • what magnification does it provide? (NB: Magnification = dioptres divided
    by 4. See table about magnification.)
  • with what print size should the aid be used?
  • what instruction has student already been given?

Focal distance chart

This should be used as a guide to the correct use of a magnifier.

Dioptres Power Focal distance (in inches) Focal distance (cm)
+2 0.5x 20.00 50.00
+4 1.0x 10.00 25.00
+5 1.25x 8.00 20.00
+6 1.5x 6.60 16.67
+8 2.0x 5.00 12.50
+10 2.5x 4.00 10.00
+12 3.0x 3.30 8.30
+14 3.5x 2.90 7.14
+16 4.0x 2.50 6.25
+18 4.5x 2.20 5.50
+20 5.0x 2.00 5.00
+24 6.0x 1.70 4.16
+32 8.0x 1.20 3.10
+40 10.0x 1.00 2.50
+48 12.0x 0.83 2.08
+56 14.0x 0.71 1.78
+64 16.0x 0.62 1.56
+72 18.0x 0.55 1.38
+80 20.0x 0.50 1.25

Reference: Foundations of Low Vision pp.129

The “mechanics” of reading with a magnifier

It is important to ensure that the mechanics of reading
with a magnifier are explained to the student. The first consideration
is the “perceptual span”. The idea is to get the required magnification
with the widest field of view or “perceptual span”. Reading
rate is directly influenced by the width of the perceptual span in reading.
The typical perceptual span of a mature reader is 7 to 10 letters, i.e.
amount of information the individual can decode and store in short-term
memory in one fixation, before going on to next piece of information.
A typical length of a saccade (the movement of the eye between fixations
on the print) is 5 to 7 words or the width of newspaper columns. Students
will often start reading with their eyes some distance from the magnifier,
until they realise that with the eye closer to magnifier, their perceptual
span widens. The student needs to be taught how to widen their perceptual
span, i.e. get their eye/s closer to the magnifier.

If the optometrist prescribes a magnifier to be used with
spectacles, we need to ask if, for sustained reading it can be used without
spectacles to decrease the distance from the eye to the magnifier.

Eye-hand coordination is another important skill for a magnifier reader
and is one of the reasons that magnifiers are not often prescribed to children
below about year 3. (The other reason being that young children can accommodate
so close that they often get sufficient magnification from bringing the
print very close.) Movement of an unsteady hand is “magnified”on
the page. The magnifier lens must remain parallel to the page. Any tilt
will exaggerate lens aberrations. This may not be immediately apparent to
a student with low vision.

Another important skill involves tracking and eye movements.
Efficient, mature readers utilise smooth, rightward saccades with few
regressions. Low vision readers using magnifiers have been found to adopt
“saw-tooth” eye movements. These are caused by the eye following
the apparent leftward movement of the print as the magnifier is moved
to the right. The “saw-tooth” movement lowers reading speed
and comprehension and increases fatigue (Fotinakis & Dickinson, 1994).
Any training must attempt to minimise this. Also, the velocity of smooth
eye movements must be well matched to that of the moving letters under
the magnifier, otherwise comprehension is lost.

Lighting must also be considered. The magnifier may occlude
light so the student must be made aware of where to position himself in
relation to light when using the magnifier.

The teaching of reading with a magnifier

Positive modelling is often neglected for students with
vision impairments because they are invariably the only student with vision
problems in their school. Students need the opportunity to meet with and
observe proficient readers with magnifiers. It is difficult to be confident
about mastering a new skill if you’ve never known anyone else capable
of it.

I stress again the importance of teaching the student about
the mechanics of reading with a magnifier. Students must understand how
to find the focal distance and how to vary their perceptual span. One
optometrist suggests attaching a piece of string to the magnifier with
a knot to indicate how far it should be held from the page. The student
should also understand the implications of and the need for smooth, rightward
eye movements. You should also explain that initially reading may be slower
as the student concentrates on use of the device rather than the reading

Should the student move the page or move the magnifier and
eyes? This depends on the task and the type of material. It is OK to move
a single page flat on a table top or reading stand. This becomes a bit
too difficult with books.

The student will need to do some reading exercises with
the magnifier to build up their skills. I would not recommend isolated
letter or word exercises as the student should be trying to maximise his/her
perceptual span.

Start with the print size recommended by the optometrist.
Try larger print if the student is not coping, or go smaller if s/he is
coping well. The student should be able to reduce the initial print size
with practice.

The first exercise should comprise short phrases, well spaced
between columns and lines. (See reading exercise charts.) The student
can start with one column, moving to several columns, practicing smooth
rightward movements. We should always try to spark the interest of our
students. Make up phrases which will amuse, take phrases from a favourite
book or pick a pet topic eg football.

If the student has difficulty tracking, use an “aperture”
– a piece of cardboard which occludes all but one line of print. First
use a black aperture on white paper, then grey, then a fine line under
the print, then a ‘white’ mask so the student is reading only
one line. (Use white cardboard on the white page to occlude all but the
one line without giving a contrasting aperture.) This will move the student
away from concentrating on the aperture for tracking, and onto tracking
the line of print.

Use a pointer at the beginning of the line, if movement
from one line to the next causes difficulties.

Move to columns of text (of interest to the student). For
this, one can use magazine articles about footy stars, kids magazines
articles or any short, factual, interesting stories. Again use “apertures”,
if needed. Aim not to use these permanently as the magnifier is enough
to handle.

Finally, move to normal reading materials. Hard backs are
easier than paper backs as the student needs to sit the book flat and
paper backs don’t open absolutely flat. As manual skills increase,
give the student a specific purpose for reading (eg find out answer
to question) so that his/her focus moves away from the magnifier and onto
the reading task.

See Ideas for encouraging reading with a magnifier

Increasing reading speeds

Typical reading rates for mature readers – oral and
silent reading rates (in words per minute)

Year level Minimum oral reading rates Typical silent reading rates
1 60 less than 81
2 70 82-108
3 90 109-130
4 120 131-147
5 120 148-161
6 150 162-174
7 150 175-185
8 186-197
9 198-209
10 210-224
11 225-240
12 241-255
College 256-333 or more

Reference: Foundations of Low Vision pp.259

rates for people with low vision (in words for minute)

Central Field Ocular Media
Clear Cloudy
Intact 131 95
Loss 39 29

Reference: Foundations of Low Vision pp.284

Teachers often believe that low reading rates are a natural
outcome of having low vision and hence do not attempt to provide training
to improve skills. Suggesting that the low vision student does every second
question or reads fewer books because of time limits, whilst often practical,
perpetuates the low vision student’s poor skills and stamina and
disadvantage in exposure to reading. Good readers become so through reading!

for increasing reading fluency and speed

Reference: Corn & Koenig, 1996


  • short, interesting stories (3-5 min.)
  • read and time
  • re-read and re-time
  • make student aware of rate increase
  • repeat several times


  • choose classmate with similar reading level but faster
  • have VI student read a passage on own (silently will
  • let classmate read passage aloud while VI student follows
  • then two read together
  • VI student will try to match speed of classmate


  • select easy reading material for a small group of children
    including VI student
  • read aloud together
  • since no-one is ‘on stage’ this is a comfortable
    way for slower students to try to match speed of faster readers


  • similar to choral reading, but teacher and student read
  • direct student to disregard meaning and concentrate
    on smooth eye movements
  • teacher gradually increases rate of reading as passages
    are repeated


Vision impaired students should be taught to recognise the
signs of both visual and postural fatigue. Offer the student strategies
to deal with them. For example:

  • take short breaks
  • close eyes
  • look into distance
  • change task – listen to audio book for a while
  • shift physical position of arms, neck, back, shoulders,

The student may also try relaxation techniques. “Imagine
a knot behind your eyes, close eyes and imagine the knot gradually untying,
think of a peaceful place, ……….”


Tables are great to read with magnifiers because they are just like reading
columns. The student may need to revert to the use of an “aperture”
if there are long gaps between columns. Ensure that the student is aware
of the labelling conventions of tables.

For graphs, the student needs to look at it without the magnifier first.
Although the student won’t see detail, s/he can see the overall shape
of the graph. If you use a photocopy of graphs in books, the teacher can
circle specific parts to teach certain concepts. Again, the student may
need an “aperture” to track to points. Also, as with tables, ensure
that the student understands the conventions of labels on graphs. There
are some good mainstream books available to teach graphing skills. Use these
as part of your student’s magnifier training, if the student requires

For pictures and diagrams, again it helps to look at diagrams
without the magnifier first. Diagrams are difficult to perceptualise in
small chunks and there are few conventions to rely on. The student’s
instructions may need to be specific to individual diagrams. For example,
instruct the student to use the key, read labels and follow arrows to
diagram part, whether the diagram is shown with or without perspective.

The beauty of using a magnifier with diagrams is that the
student can use the colour copy instead of a black & white enlargement.

to tell teachers when your student reads with a magnifier

Teachers should be told to expect a slower reading speed
(at least initially!). It is helpful if they are made aware of some of
the mechanics such as the fixed focal distance and that a close reading
distance OK and often necessary when using the aid.

Teachers need to know that, whilst the aid will solve many
problems it may create a few, too. Visual and postural fatigue may be
increased at least in the early stages of using the magnifier. The student’s
field of view will be reduced by the aid. This is especially important
when viewing graphics.


Although there are some disadvantages to using a magnifier
and students need to commit to some training and practice, their independence
and options for reading will be unlimited if the skill is attained. This
skill will remain with them beyond their school years when large print
will be much more difficult to obtain.


Corn, A., Optical Devices or Large-Type: is there a debate?
Paper presented at International Conference on Low Vision, 1990

Corn, A. & Koenig, A. Ed., Foundations of Low Vision:
Clinical & functional perspectives, AFB Press, New York, 1996.

Fotinakis, V. & Dickinson, C., “Reading with magnifiers”
in Low Vision – Research & new developments in rehabilitation by Kooijman,
Looijestijn, Welling 7 Wildt, IOS Press, Netherlands, 1994.

Spitzberg, L., Goodrich, G. & Perez-Franco, A. “Reading
with vertical magnification with Retinitis Pigmentosa” in Low Vision
– Research & new developments in rehabilitation by Kooijman, Looijestijn,
Welling 7 Wildt, IOS Press, Netherlands, 1994.

Paper presented by Marion Blazé, Education Officer, Statewide Vision
Resource Centre