Why Can You Read Something If You Squint That You Couldn't Otherwise...

[sandyRoe]

...without your specs?

[bert_h]

Because squinting limits the visual input to a small part of your slightly deformed eyeball. If you allow the rest of your eyeball to add to the image, it doesn't line up properly, so it blurs. Narrow the field again, and it sharpens up.

[Bazile]

I suppose it's because by squinting , more of the light is concentrating into your pupils and your'e decreasing peripheral vision

[jennyjoan]

It is time you were getting to Specsavers Sandy.

[Hopkirk]

I think when light passes through a narrow aperture some of it is refracted causing a small amount of magnification.

Try curling your finger so there is a tiny hole and look through that - it acts as a magnifying lens.

[seadogg]

You can get the same effect by looking through a pinhole or crooked finger. Just be careful who you crook at.

[jeffa]

http://en.wikipedia.org/wiki/Pinhole_glasses

[seadogg]

Hadn't seen your erudite post when I added mine Hopkirk.

[Hopkirk]

I was partly blagging it though, so was pleased not to be shot down in flames

[Bazile]

You're sometimes asked to read a chart at the opticians (or elsewhere ), looking through a pinhole .

The image is always sharper

[sandyRoe]

All good answers. TY. First up, best dressed, so best answer goes to bert_h.

[ghgraham]

Squinting reduces the effective aperture of the eye, thus increasing the depth of field and making images appear sharper.

[Prudie]

It is rather comforting though, proves you do still have the ability to see clearly