Understanding LASIK

What Does LASIK Fix?

LASIK eye surgery is used to fix refractive errors, but first, let’s discuss some background on how the eye works and define the terms commonly used in the eye care field. Your “refractive error” is the measurement or prescription that tells us how to optically correct your vision. In order to calculate this, we perform a number of tests that measure how light and images pass through your eye. We measure how light refracts or bends, as it passes through your eye’s cornea (outer window of the eye) and lens (inside the eye) to focus on the back surface of your eye (the retina) to form a picture that your brain processes. One way to think of how your eyes work is to think of the inner workings of a camera.

Refractive Error Example

The front surface, or cornea, has certain magnification power just like a camera lens, but your cornea is not always shaped perfectly like a camera lens. When the cornea is not perfectly shaped, the images cannot be clearly projected onto your retina. This causes imperfections or refractive errors that are described below. Once images pass through the cornea, a second interior lens, which is flexible when we are young, also helps to focus the image on the retina.

When we test your vision, we measure the focusing strengths of both the cornea and the natural lens and how they work together so we can determine what we need to do to help you achieve your best possible vision

What Refractive Errors Does LASIK Correct?

Myopia (Nearsightedness)

Nearsightedness occurs when the cornea is too steep or the eye is too long. This means the light that enters the eye focuses in front of the retina causing far and intermediate objects to appear blurry.


Hyperopia (Farsightedness)

Farsightedness occurs when the cornea is too flat or the eye is too short. This causes light to focus past the retina resulting in blurry near or intermediate vision. Those who have high amounts of farsightedness are very dependent on glasses or contacts; however, many people who are only slightly farsighted may not realize focusing problems until they are in their 40s.



Astigmatism is caused by an irregularly shaped cornea or lens and can occur along with nearsightedness or farsightedness. In a perfect eye, the cornea should be uniformly curved in all directions like a bowl, but with astigmatism, it is shaped more like the back of a spoon – with a rounder dimension and a flatter dimension – resulting in a blurred or double vision at all distances.



Presbyopia (a need for reading glasses) Presbyopia occurs when the interior lens of the eye loses its ability to change focusing power simply because of age. As we age, this lens becomes less flexible. On average, around ages 40 to 50, most people gradually lose the ability to see up close when performing activities such as reading a newspaper, book, or menu. You will notice that presbyopia develops progressively so that reading or near vision will continue to worsen and become blurrier over time.

Many people nickname presbyopia “the long-arm disease” because they develop the need to hold reading materials farther and farther away. Eventually, this condition may also affect your intermediate vision, such as working at computers. Our presbyopic patients typically benefit from either presbyopia correction with the Raindrop inlay, blended vision LASIK (one eye focused for near), or replacing the natural lens with a lens implant.

The best choice among these options varies from patient to patient, so we recommend a consultation to discuss how these differences are relevant to your unique eye anatomy.


If you are presbyopic or beginning to struggle up close without reading or bifocal glasses, you could elect to have blended vision with most of the vision correction procedures offered by Slade & Baker Vision. Blended vision features correction for distance vision in one eye and nearer vision in the other eye. This balance can be custom planned for your activities and lifestyle to maximize the useful range of vision and depth perception.

In order to determine if you are a good candidate for blended vision, your doctor may have you simulate blended vision using contact lenses for a short time. Many people have already experienced blended vision with their contacts, and these patients are excellent candidates for a blended vision correction procedure.

Different Types of LASIK Procedures and Technology

Since no two eyes are the same, you can feel confident that with the advantage of having a variety of the latest and most advanced technology, along with Dr. Slade’s experience and commitment to continuous quality improvement, that you will have the best results and best care with your custom procedure here at Slade & Baker Vision Center.

What technology is used in LASIK eye surgery?

We use multiple refractive surgery lasers. With LASIK, we use a femtosecond laser to make the flap, and an excimer laser to do the treatment. With SMILE (Small Incision Lenticule Extraction), we use a femtosecond laser to delineate a small, lens-shaped portion from the cornea, which we carefully remove through a minimally invasive incision.

We use the Zeiss Visumax laser, the Alcon Allegretto Wavelight Femtosecond and Excimer lasers, and the LenSx laser for cataract and corneal surgery. The Allegretto Wavelight excimer laser measures the eye 400 times per second to ensure highly accurate contouring for advanced visual outcomes. Dr. Slade has found that Allegretto’s technology is particularly beneficial to patients with higher myopia.

Dr. Slade is often the first to have access to new laser technologies through clinical trials. As such, we anticipate debuting two additional new lasers in the near future, though we are unable to release more details at this time.

Why do you have multiple different lasers to do LASIK and Laser Vision Correction?

“We have two different lasers that make the ablation, two different lasers that make flaps. There’s a very simple answer to why we have four lasers for LASIK. Because we have more than one patient. And by that I mean our patients are so varied. People are different. Some people have a lot of nearsightedness. Some people have a lot of astigmatisms, while some have this requirement or that requirement.

So we find that we use different lasers for different eyes. Different prescriptions. And we find the sweet spot. So we’re able to better offer the patient what might be a solution that suits their eye, their individual eye better. The more tools you have – it just makes sense. And it’s helped us with our results.” – Stephen Slade, M.D. 

What is Custom LASIK?

With Custom LASIK, we take more measurements and create a procedure that is more specific to your eye. This procedure may be wavefront-guided, wavefront-optimized, or a blend of our measurements. It’s like having a suit custom-made for you, rather than buying one off the rack.  The fine points of your vision are treated.  During your free consultation, we can answer any questions regarding your vision or your treatment options.

The custom or wavefront exam covers thousands of points across the entire visual system of your eyes with our wavefront diagnostic devices.

Until recently, LASIK treatments were strictly based on a patient’s optical prescription.  They did not take into account that each patient’s eyes have a unique set of naturally occurring optical imperfections.  This was known as conventional LASIK.”

Today, with the advent of wavefront diagnostic technology, wavefront-guided and wavefront-optimized excimer lasers can now treat patients according to the uniqueness of their eyes, not just their prescription.

Wavefront technology compares distorted waves of light exiting the eye to flat waves of light that would have returned in a perfect optical system.  This information is converted to a 3-D Map that then serves as a guide for the excimer laser to reshape the cornea.

Another technique Dr. Slade uses is “wavefront-optimized.” This is the newest treatment pattern approved by the FDA and offers superb results for many patients.

What is Bladeless LASIK Eye Surgery?

LASIK is performed under a hinged flap of corneal tissue. Once the flap is created and folded back, the excimer laser removes corneal tissue, reshaping the underlying tissue to correct any vision abnormalities. The corneal flap is then relocated over the treated area where it bonds with no need for stitches. LASIK patients experience little if any discomfort. Functional vision returns very rapidly, with the majority of patients seeing well enough to drive in a day or two, without the need for glasses or contact lenses.

During the first step of the LASIK procedure, a corneal flap is made.  In the past, the corneal flap was created by a mechanical device which used a blade (microkeratome). Today, we offer our patients ALL LASER LASIK using the IntraLASE® femtosecond laser to create the corneal flap, thereby adding a higher level of safety and precision to the LASIK procedure.

Using this Blade-Free LASIK procedure, the IntraLase laser delivers over millions of tiny, micron-sized bubbles that gently separate the layers of corneal tissue. This creates a customized corneal flap of the desired thickness, size, orientation, and location. This unprecedented level of control also allows more patients to qualify for LASIK and virtually eliminates many of the complications associated with the past mechanical approach.

What is all-laser LASIK and why do you think it’s better?

All-laser Lasik is using two lasers on each eye. Both components. Remember, LASIK is making a very thin flap of corneal tissue, laying the flap back and then reshaping the eye with a laser, replacing the flap. Initially, we used a metal blade to make that flap. And that was back in 1991 when we started Lasik and did the first ones. And then [we use] the laser to reshape. All-laser LASIK is using a laser to make the flap, and then a second laser to reshape the eye.

We actually have the nation’s longest experience in all-laser LASIK as well as LASIK. We went to it early. Well, we went to it earlier than anybody, because it simply made sense. A laser can make a flap more precisely with unique safety factors that you simply do not have in a metal blade. The metal blade was great. But the laser was an improvement in technology. It gave us so many different options.

Take our LASIK Self-Test to find out if you may be a candidate for LASIK surgery or not.

If you have questions, please do not ever hesitate to call our office at 713-626-5544 and speak to our experts and schedule a consultation today!

The doctors at Slade and Baker Vision have either authored or reviewed and approved this content.

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Houston, TX 77027

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3900 Essex Lane - Suite 101 - Houston, TX 77027  -  713-626-5544