Sunlight

[Adam1234]

Hello, I'm seven months post graft and have nine stitches remaining.it may be a stupid question but when I'm indoorsy
Vision is okay but still quite blurry! Outdoors when the sun is shining my vision is almost crystal clear can anyone explain this?

Thanks Adam

[longhoc]

Hi Adam, I get exactly the same. I think it is due to the dilation of the iris / pupil in doors (and the opposite when you're outdoors, especially in bright sunlight).

At low ambient light levels like you get indoors, the pupil is pretty much totally dilated. This means that more of the perimeter of your grafted cornea (which isn't nearly completely healed yet at this stage and is still to a degree quite opaque in places -- certainly where the stitches either are or have only recently been removed) is exposed. Because the quality of the tissue isn't as good, you get the blurryness.

Conversely, in bright light the pupil narrows, the light only has to pass through the middle bit, which is comparatively in good shape. So everything is sharp(-er).

Have you noticed too how putting on sunglasses turns that sharp outdoor image back to blur again ? I think it's the same reason -- your pupils open out a bit, the light then has to pass through the outer edge of the graft.

That's my theory. There may be some other more complicated factors to do with optics. Maybe there's a better explanation available from someone who's actually asked the question of a professional ? !

Cheers

Chris

PS good luck during the rest of the post op period !

[GarethB]

Many many years since I experienced this, but it is much the same affect as when we try pin hole glasses.

[Lynn White]

Chris is essentially correct - its the pinhole effect of a small pupil.

I am assuming that this is without any spectacle correction? If so, then you might be able to get it cleared up with a pair of glasses.

Lynn

[GrandPaClanger]

I get the same results. Being into photography I have always assumed its a " depth of field" effect. By decreasing the aperture (iris) of lens on a camera you increase the distance in front and behind a subject that objects will remain in focus. For example when taking a portrait photograph you would open the iris of the camera up so that the model is in focus but the background is blurred. Well that's my theory anyway .

Ian