Magnification Methods

There are four ways to make objects look larger

1. Bring object close: 2X closer makes object 2X bigger
   An object close to the eye requires a lot of accommodation.
   This is possible for children but is more difficult for adults. Children can magnify print and small objects by holding them very close to their eyes, so some children will not need magnifiers to see near objects
   
2. Enlarge the object
3. Use an optical device
4. Electronic and projection magnification

Who prescribes low vision devices?

• eye care personnel or a person specialised in low vision will assess a person's visual needs, prescribe a magnifier and trial the effect of magnification

When to try magnification?

• magnification is tried if the near vision is not good enough for the tasks he/she needs to do
• in general, when near vision is N10, or larger magnification should be tried so that school books, newspapers etc. can be read
• not all people with low vision will benefit! Magnification is not clarification, it only provides a larger image. Hazy vision from corneal clouding stays hazy when magnified but more details can be seen

When trying magnifiers, check:

• the person's speed of reading/writing
• how easy it is to use - hand held or movement of the magnifier
• how much can be read through the magnifier at one time
• the distance the person needs to be from the page to read

The higher the magnification (stronger the lens):

• the less you see in one go (the smaller the field of view)
• the closer the reading distance (i.e. eye to the magnifier)

Simulation

Help

Always use a device with:

• the least magnification possible
• enough visual improvement
• comfortable working distance

Checkpoint:

How can objects or print be magnified?

Why should the lowest possible magnification be prescribed?