a good method for people with extra thin or steep corneas.

Cutting a flap on the surface of an eye that has an average corneal thickness is not problematical, although of course it must be done very carefully and precisely. If your cornea is extra thin, that will disqualify you for traditional LASIK, but not for PRK, since no flap will be cut at all. If your cornea is extra steep, that increased curvature increases the risk of cutting a flap incorrectly, perhaps with a hole in the middle, or cut too deeply. This also disqualifies you for traditional LASIK, but not for PRK.

PRK Fact #3: The corneal epithelium will regrow in a matter of days.

The surgeon has removed those surface cells permanently, but the cornea will replace them. This takes five or six days, during which time you need to wear that bandage contact lens for protection.

PRK Fact #4: Recovery time is longer than

Here are five facts about PRK. To understand them, we first need some background information.

Not everybody is a good candidate for traditional LASIK surgery. Over the past decade or so several good LASIK variations have been developed so that more people can benefit from refractive surgery.

All the LASIK variations are known as refractive surgery. Refraction is the bending of light rays by a lens of some type. In our eyes we have a lens that bends light rays as they enter our eye. We also have the cornea, which acts as a lens and bends those light rays even more than the lens does. In fact, it does 75% of the bending.

What is the cornea?
It’s the clear part in the front of the eye, through which we can see a person’s eye color and pupil. It has a curved shape, so that when light rays enter it, they are bent at an angle, which varies according to two factors:

· The exact curvature of the cornea
· The distance from which the light rays have traveled to the eye. Light from far objects is bent less than light from near objects.

All types of LASIK surgery increase visual clarity by correcting the curvature of the cornea. When a cornea is too steep, it bends light rays too much, so that instead of focusing on the retina, they focus in front of it (nearsightedness). When a cornea is too flat, it bends light too little, causing those rays to focus behind the retina (farsightedness).

What is the retina?
It’s the inside back surface of the eye, with light-sensitive cells, and special cells that pick up color. The eye’s main nerve, the optic nerve, connects to the retina, receiving neural information from it about images brought by the light rays. The optic nerve carries this information to the brain, which interprets it, finds a name for it, and presto! We know we’re looking at a woolly sheep and not a dog or baby deer. In a normal eye, that woolly sheep is very clear and can’t be mistaken for a dog or deer. In a nearsighted or astigmatic eye it might look so blurry that it could be a dog or deer. In a farsighted eye, it might be perfectly clear if it’s the right distance away for your individual degree of farsightedness. But if it approaches you, it will become increasingly blurry.

Correcting the cornea
In a LASIK treatment, the laser is focused with extraordinary precision on particular tiny spots on the cornea. The exact spots, their number, and the depth to which they’ll be treated, are determined by your LASIK surgeon beforehand, in a well-thought-out treatment plan for your particular eyes. The laser vaporizes these tiny spots, changing the curvature of the cornea.

The cornea has layers and the surface layer, the epithelium, is soft and fast-growing. Beneath it is the stroma, which does not regrow, and this is where the LASIK treatment is done. That means that somehow, some epithelial cells need to be removed to give the laser access to the stroma. In traditional LASIK, this is done by first cutting a thin flap of surface tissue and bending it back while treatment is done, then replacing it. This flap is about as thin as the width of a human hair.

PRK Fact #1: No flap is created.

Instead, a laser (or sometimes a surgical tool and certain chemicals) is used to vaporize a thin layer of epithelial cells. Now the surgeon can treat the stroma underneath, reshaping the cornea according to your treatment plan. Afterwards, he places a bandage contact lens over the treated area, instead of replacing any flap. Both methods give protection to the stromal layer as the cornea heals its surface layer.

PRK Fact #2: PRK is a good method for people with extra thin or steep corneas.

Cutting a flap on the surface of an eye that has an average corneal thickness is not problematical, although of course it must be done very carefully and precisely. If your cornea is extra thin, that will disqualify you for traditional LASIK, but not for PRK, since no flap will be cut at all. If your cornea is extra steep, that increased curvature increases the risk of cutting a flap incorrectly, perhaps with a hole in the middle, or cut too deeply. This also disqualifies you for traditional LASIK, but not for PRK.

PRK Fact #3: The corneal epithelium will regrow in a matter of days.

The surgeon has removed those surface cells permanently, but the cornea will replace them. This takes five or six days, during which time you need to wear that bandage contact lens for protection.

PRK Fact #4: Recovery time is longer than f

curvature of the cornea
· The distance from which the light rays have traveled to the eye. Light from far objects is bent less than light from near objects.

All types of LASIK surgery increase visual clarity by correcting the curvature of the cornea. When a cornea is too steep, it bends light rays too much, so that instead of focusing on the retina, they focus in front of it (nearsightedness). When a cornea is too flat, it bends light too little, causing those rays to focus behind the retina (farsightedness).

What is the retina?
It’s the inside back surface of the eye, with light-sensitive cells, and special cells that pick up color. The eye’s main nerve, the optic nerve, connects to the retina, receiving neural information from it about images brought by the light rays. The optic nerve carries this information to the brain, which interprets it, finds a name for it, and presto! We know we’re looking at a woolly sheep and not a dog or baby deer. In a normal eye, that woolly sheep is very clear and can’t be mistaken for a dog or deer. In a nearsighted or astigmatic eye it might look so blurry that it could be a dog or deer. In a farsighted eye, it might be perfectly clear if it’s the right distance away for your individual degree of farsightedness. But if it approaches you, it will become increasingly blurry.

Correcting the cornea
In a LASIK treatment, the laser is focused with extraordinary precision on particular tiny spots on the cornea. The exact spots, their number, and the depth to which they’ll be treated, are determined by your LASIK surgeon beforehand, in a well-thought-out treatment plan for your particular eyes. The laser vaporizes these tiny spots, changing the curvature of the cornea.

The cornea has layers and the surface layer, the epithelium, is soft and fast-growing. Beneath it is the stroma, which does not regrow, and this is where the LASIK treatment is done. That means that somehow, some epithelial cells need to be removed to give the laser access to the stroma. In traditional LASIK, this is done by first cutting a thin flap of surface tissue and bending it back while treatment is done, then replacing it. This flap is about as thin as the width of a human hair.

PRK Fact #1: No flap is created.

Instead, a laser (or sometimes a surgical tool and certain chemicals) is used to vaporize a thin layer of epithelial cells. Now the surgeon can treat the stroma underneath, reshaping the cornea according to your treatment plan. Afterwards, he places a bandage contact lens over the treated area, instead of replacing any flap. Both methods give protection to the stromal layer as the cornea heals its surface layer.

PRK Fact #2: PRK is a good method for people with extra thin or steep corneas.

Cutting a flap on the surface of an eye that has an average corneal thickness is not problematical, although of course it must be done very carefully and precisely. If your cornea is extra thin, that will disqualify you for traditional LASIK, but not for PRK, since no flap will be cut at all. If your cornea is extra steep, that increased curvature increases the risk of cutting a flap incorrectly, perhaps with a hole in the middle, or cut too deeply. This also disqualifies you for traditional LASIK, but not for PRK.

PRK Fact #3: The corneal epithelium will regrow in a matter of days.

The surgeon has removed those surface cells permanently, but the cornea will replace them. This takes five or six days, during which time you need to wear that bandage contact lens for protection.

PRK Fact #4: Recovery time is longer than

e know we’re looking at a woolly sheep and not a dog or baby deer. In a normal eye, that woolly sheep is very clear and can’t be mistaken for a dog or deer. In a nearsighted or astigmatic eye it might look so blurry that it could be a dog or deer. In a farsighted eye, it might be perfectly clear if it’s the right distance away for your individual degree of farsightedness. But if it approaches you, it will become increasingly blurry.

Correcting the cornea
In a LASIK treatment, the laser is focused with extraordinary precision on particular tiny spots on the cornea. The exact spots, their number, and the depth to which they’ll be treated, are determined by your LASIK surgeon beforehand, in a well-thought-out treatment plan for your particular eyes. The laser vaporizes these tiny spots, changing the curvature of the cornea.

The cornea has layers and the surface layer, the epithelium, is soft and fast-growing. Beneath it is the stroma, which does not regrow, and this is where the LASIK treatment is done. That means that somehow, some epithelial cells need to be removed to give the laser access to the stroma. In traditional LASIK, this is done by first cutting a thin flap of surface tissue and bending it back while treatment is done, then replacing it. This flap is about as thin as the width of a human hair.

PRK Fact #1: No flap is created.

Instead, a laser (or sometimes a surgical tool and certain chemicals) is used to vaporize a thin layer of epithelial cells. Now the surgeon can treat the stroma underneath, reshaping the cornea according to your treatment plan. Afterwards, he places a bandage contact lens over the treated area, instead of replacing any flap. Both methods give protection to the stromal layer as the cornea heals its surface layer.

PRK Fact #2: PRK is a good method for people with extra thin or steep corneas.

Cutting a flap on the surface of an eye that has an average corneal thickness is not problematical, although of course it must be done very carefully and precisely. If your cornea is extra thin, that will disqualify you for traditional LASIK, but not for PRK, since no flap will be cut at all. If your cornea is extra steep, that increased curvature increases the risk of cutting a flap incorrectly, perhaps with a hole in the middle, or cut too deeply. This also disqualifies you for traditional LASIK, but not for PRK.

PRK Fact #3: The corneal epithelium will regrow in a matter of days.

The surgeon has removed those surface cells permanently, but the cornea will replace them. This takes five or six days, during which time you need to wear that bandage contact lens for protection.

PRK Fact #4: Recovery time is longer than

soft and fast-growing. Beneath it is the stroma, which does not regrow, and this is where the LASIK treatment is done. That means that somehow, some epithelial cells need to be removed to give the laser access to the stroma. In traditional LASIK, this is done by first cutting a thin flap of surface tissue and bending it back while treatment is done, then replacing it. This flap is about as thin as the width of a human hair.

PRK Fact #1: No flap is created.

Instead, a laser (or sometimes a surgical tool and certain chemicals) is used to vaporize a thin layer of epithelial cells. Now the surgeon can treat the stroma underneath, reshaping the cornea according to your treatment plan. Afterwards, he places a bandage contact lens over the treated area, instead of replacing any flap. Both methods give protection to the stromal layer as the cornea heals its surface layer.

PRK Fact #2: PRK is a good method for people with extra thin or steep corneas.

Cutting a flap on the surface of an eye that has an average corneal thickness is not problematical, although of course it must be done very carefully and precisely. If your cornea is extra thin, that will disqualify you for traditional LASIK, but not for PRK, since no flap will be cut at all. If your cornea is extra steep, that increased curvature increases the risk of cutting a flap incorrectly, perhaps with a hole in the middle, or cut too deeply. This also disqualifies you for traditional LASIK, but not for PRK.

PRK Fact #3: The corneal epithelium will regrow in a matter of days.

The surgeon has removed those surface cells permanently, but the cornea will replace them. This takes five or six days, during which time you need to wear that bandage contact lens for protection.

PRK Fact #4: Recovery time is longer than

a good method for people with extra thin or steep corneas.

Cutting a flap on the surface of an eye that has an average corneal thickness is not problematical, although of course it must be done very carefully and precisely. If your cornea is extra thin, that will disqualify you for traditional LASIK, but not for PRK, since no flap will be cut at all. If your cornea is extra steep, that increased curvature increases the risk of cutting a flap incorrectly, perhaps with a hole in the middle, or cut too deeply. This also disqualifies you for traditional LASIK, but not for PRK.

PRK Fact #3: The corneal epithelium will regrow in a matter of days.

The surgeon has removed those surface cells permanently, but the cornea will replace them. This takes five or six days, during which time you need to wear that bandage contact lens for protection.

PRK Fact #4: Recovery time is longer than for traditional LASIK.

When a flap is created, folded back, and then replaced, it’s the eye’s own tissue, and heals up very quickly indeed. When the cornea must create new epithelial cells to replace lost ones, it takes longer. A traditional LASIK patient does not need to wear any bandage contact lens, because the flap acts as a bandage. A PRK patient needs to use good self-care after the procedure for perhaps two weeks, and sometimes a month or so, as the eyes completely heal.

The eyes may be a bit watery, sensitive to light, and sore, as if there’s an eyelash or something in there. A prescription painkiller takes care of any discomfort, and as long as you refrain from rubbing your eyes, doing too much reading or computer work, or getting too little sleep, recovery will be over in a matter of weeks and you’ll have a lifetime of clear vision ahead of you.

PRK Fact #5: The results are typically astounding.

If you have been near- or far-sighted all your life, or astigmatic, and have used glasses or contact lenses for years, you’ll be ecstatic at your new clear vision! You’ll see a lot of improvement as soon as the bandage contact lenses are removed, and even more as the next few weeks go by.

At Griffin and Reed Eye Care in the Sacramento area, California, the work of improving people’s vision remains perpetually exciting. Their patients are more than pleased: they’re amazed and grateful, and many of them give testimonials, such as this one:

A miracle! One of the best decisions of my life. Griffin & Reed Eye Care's staff was extremely considerate and kind and made it the best medical experience I have ever had.
- Cheri K.