Questions and perspectives about eyes and vision.
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You might initially think that having dry eyes wouldn’t make that much difference to your vision, but it can.
People can get dry eyes for a number of reasons, but most of the time, it’s not lack of tears (quantity) that’s the problem, but rather instability (quality) of the tear film that creates the dry eye symptoms.
The eyes have a thin film of tears on them all the time, and to keep clear vision, that film needs to be stable. After a blink, when the tear film gets reset, the tear film will remain stable for a number of seconds. Hopefully this period is long enough to preserve a smooth front surface to the eye until your next blink occurs. If you hold your eyes open long enough, you’ll feel the sting, and perhaps the blur, that comes as that tear layer loses its structure, and dry patches develop on the front of the eye. The sting comes because the nerves in the cornea are very sensitive, and let you know as soon as the tear film has broken down. The blur comes because the front surface of the eye, a very important part of the optics of the eye, is no longer as smooth.
A rough front surface to the eye means that light falling on it will not be focussed regularly, but instead, light will get scattered in different directions. This may be
Usually, having a blink will restore the regularity of the tear film, but if the eyes have been getting dry for a while, then even the ‘reset’ tear film won’t be as stable, and the symptoms will remain no matter how much you blink.
Therapy for dry eye can be targetted towards:
Dry eye vision symptoms seem to be more common amongst people working at computer screens and contact lens wearers.
There are of course, many other things that can cause blurry vision, but dry eye is definitely one of them.
Written by Russell
6 July, 2009 at 7:40 pm
Posted in Eyes, Vision and Optical Things
Tagged with blurred vision, blurry dry eyes, computers, contact lenses, dry eyes, eye drops, eyes, filmy vision, glare, gritty eyes, hazy vision, tear film, tired eyes
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