Whats the technique called where I look on the outside .....

[fuggles]

For example, if I sketch the lining of a letter on the Snellen chart but dont look directly at the letter, whats the name of this exercise.

It helped a lot from just looking at the top letter on the Snellen chart and just sketching the lining og the letter without looking at it.

[David]

You mean looking at the white halos around the letters?

Dave

[fuggles]

Yes, something like that.

I outline the letters. But not specifcially the halos.

Or the leg of table etc etc

[clarknight]

Trace along and on the edge of the object.
You must use central fixation; look at the object you want to see clear.
Looking at the the area away from the object, on the side of it, even if it is close to the object is going against central fixation.
Moving the eyes/viusal attention directly on/along the fine edge of a object, parts of the object is perfect central fixation and brings clear fine tuned vision.

Looking at the halos is healthy for the eyes, but when looking at the halos; look directly at the halo to see the halo, (do not try to see the object and halo at the same time with the center of the visual field) or, you can; let the halo appear in the peripheral field when looking at the object.
You can shift back and forth from halo to object, object to halo.
The halo in the peripheral field is close the the edge of the object and is brightest closest to the edge of the object.
Example; the area of a white page appears brightest, whitest on the area closest to the black ink of a letter on the page.
People used to advise reading by moving the visual attention along the bright white spaces between sentences.
This is diffusion, the opposite of central fixation.
But... being able to see the white bright halo/space appear between sentences, moving the eyes, center of the visual field along it without trying to see the words, being able to see the white halo around letters, words, and a thin bright white line under a sentence is ok and brings vision improvement.
This is hard to describe, i am trying to emphasize to maintain central fixation; look at the object you want to see.
Let the peripheral vision see halos, or look directly at the halo to see it.

[fuggles]

thanks,

I try not to even though its at the back of my mind not to look at it

[textus]

Erm how do I see halos on the Snellen Chart? what halo is everyone referring to??

[Ram]

Halos are the "extra whites" around black letters. These halos help the mind to better resolve black letters by providing an improved contrast. You can see them only if you see well - if your vision is defective you can hope to see halos for letters close to your eyes.

There is no way to forcibly see halos - you can see them if you can relax enough to improve your vision. You can try to notice halos initially while reading a book.