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Whither btrfsck?

Whither btrfsck?

Posted Oct 12, 2011 22:18 UTC (Wed) by rahvin (subscriber, #16953)
In reply to: Whither btrfsck? by jg
Parent article: Whither btrfsck?

PRK and it's predecessors were in wide use in the early 80's and it was developed far earlier. What they did and what Lasik does are only different in the tool used to make the cuts. The stuff in the early 80's was done by hand with scalpels in a hospital, today it's done in an outpatient surgery through the lens with computer controlled lasers using layouts developed mostly by hand in the 80's. The most recent versions of Lasik now can map and create custom modifications of the standard cut patterns.

But basically the procedure's been in use for more than 30 years. Considering the procedure isn't even recommended until your 20's and myopia sets in at 40 the effects of Lasik on aging eyes are well understood at this point. If you are avoiding Lasik because you think it's long term effects aren't known you really need to look into it more and understand the history.

My wife went from about 20-400 with an astigmatism (before surgery got worse every year) to 20-15 and hasn't had a single problem (other than the night halos which are guaranteed). In her opinion it was the best 3 grand we ever spent. She can even see better than me and her vision is fixed by the scars, other than age related myopia her vision will never change.

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OT: myopia vs. presbyopia

Posted Dec 6, 2011 4:54 UTC (Tue) by Duncan (guest, #6647) [Link]

Myopia (near-sightedness) setting in in one's forties? Umm... Not commonly.

More like presbyopia, age related loss of focus/accommodation ability for near work, reading and the like, typically noticed first in one's 40s reading small print in dim light, and generally thought to be related to loss of crystalline lens elasticity.

There's also hyperopia aka farsightedness. Presbyopia is often called farsightedness as well, tho presbyopia is a special term for the age related loss of lens flexibility and thus near focus.

I'm highly myoptic (-11-ish diopters, too much so for good lasik results) with astigmatism (irregular or toric curvature of the cornea or lens, thing American football shaped). Hard (gas-permeable) contacts correct more accurately for the astigmatism and give me a much wider field of view without the peripheral distortion of glasses at the required corrective values. I'm also in my mid-40s and need reading glasses to reduce the contact correction (calibrated for distance vision) by a couple diopters (so to -9-ish, still highly myoptic), thus have personal experience with astigmatic myopia from early childhood, and presbyopia for a half decade or so. Thus my personal knowledge of the subject.

Wikipedia and google of course have more.


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