LASIK (laser-assisted in situ keratomileuses), is the most popular refractive surgical procedure. In this procedure, a laser is used to permanently change the shape of the cornea (the clear covering on the front of the eye) to correct common vision problems such as nearsightedness, farsightedness, astigmatism, and presbyopia. This improves vision and reduces a person's need for glasses or contact lenses.
LASIK uses an excimer laser (an ultraviolet laser) to remove a thin layer of corneal tissue, giving the cornea a new shape, so that light rays are focused clearly on the retina. In the case of a nearsighted person, the goal of LASIK is to flatten the too-steep cornea; with farsighted people, a steeper cornea is desired. LASIK can also correct astigmatism by smoothing an irregular cornea into a more normal shape.
LASIK is an outpatient surgical procedure with no need to stay at the surgery center overnight as it will take 10 to 15 minutes to perform for each eye. The procedure is done while the patient is awake, but the patient may request mild sedation. The only anesthetic used is eye drops that numb the surface of the eye. LASIK can be done on one or both eyes during the same session.
Before LASIK eye surgery, the eye surgeon will evaluate the patient’s medical history and perform a full eye examination, including measuring corneal thickness, refraction, corneal mapping, eye pressure, and pupil dilation. Afterward, the surgeon will discuss what to expect during and after the procedure.
On the day of the surgery, eat a light meal before going to the doctor and take all prescribed medications, if any. Do not wear eye makeup, creams, perfumes or lotions on the day before and the day of surgery, or have any bulky hair accessories that will interfere with positioning head under the laser.
Contact lenses shouldn't be worn for at least three days prior to the evaluation. In the case of, rigid gas permeable contact lenses, they should not be worn for at least three weeks before. Patients should arrange for a ride home from the place of surgery, as their vision might be blurry.
The LASIK surgeon uses a computer to adjust the laser for each patient’s particular prescription. An instrument to hold the eyelids open may be used and the patient will be asked to look at a target light for a short time while the laser sends pulses of light to painlessly reshape the cornea. During LASIK eye surgery, a suction ring is placed on the eye just before cutting the corneal flap that may cause a feeling of pressure and may cause vision to dim slightly. Then, an instrument called a femtosecond laser is used to create a thin flap in the cornea. The corneal flap is then painlessly peeled back and the underlying corneal tissue is reshaped using another laser. After the cornea is reshaped so that it can properly focus light onto the retina, the cornea flap is put back in place and the surgery is complete. A distinct odor might be detected as the laser removes the corneal tissue which some people describe as similar to that of burning hair, but is nothing to worry about.
The eyes might temporarily be dry even though they do not feel that way. One eye drop will be prescribed to prevent infection and inflammation and another eye drop to keep eyes moist. These drops may cause a momentary slight burn or blurring of your vision upon using them. Do not use any eye drops not approved by the LASIK surgeon.
Healing after LASIK eye surgery usually occurs very rapidly. Vision may be blurry and hazy for the first day, but most patients notice improved vision within a few days of surgery. There will be a follow-up evaluation 24 to 48 hours after LASIK eye surgery, as well as at regular intervals within the first six months.
LASIK has many benefits, including:
Vision is corrected nearly by the day after LASIK.
LASIK causes a dramatic reduction in eyeglass or contact lens dependence and many patients no longer need them at all.
Adjustments can be made years after LASIK to further correct vision if vision changes with age.
LASIK is associated with very little pain due to the numbing eye drops that are used.
No bandages or stitches are required after LASIK.
If you’ve been diagnosed with cataracts, you may wonder if cataract surgery is right around the corner. Not to worry. There are many preventive steps you can take to slow the progression of cataracts and preserve your vision. That doesn’t mean you won’t eventually need surgery, but you can at least delay the need for quite a while.
The National Eye Institute recommends protecting your eyes from the sun's harmful ultraviolet (UV) and high-energy visible (HEV) rays by always wearing good quality sunglasses while outdoors. Look for sunglasses that block 100 percent of UV rays and absorb most HEV rays with large lenses or a close-fitting wraparound style. Remember that the peak hours for sun exposure are between 10 am and 3 pm or 11 am and 4 pm during daylight savings time and that the sun’s rays are strong enough to pass through clouds, so you need your sunglasses every day.
Steroid eye drops are routinely prescribed to treat dry eyes or an arthritic flare-up in the eyes. Unfortunately, they can also speed up the progression of cataracts. Talk to your Optometrist or Ophthalmologist about how you can manage both conditions without inadvertently making your cataracts worse – and hastening the need for surgery.
There are over 300 commonly prescribed medications with side effects that may impact cataract progression. Since your primary care physician may not have access to your eye doctor’s medical records, be sure to ask your doctor if your current medications will affect your cataracts. If you must stay on the medication, it’s even more important to avoid sunlight during peak hours and to wear sunglasses.
If you haven’t quit already, here’s another good reason to do it: over time, the damage from smoking can double or triple an individual's risk of developing cataracts. If you’ve been a smoker, your habit was probably a big contributor to the diagnosis. The good news is – by quitting smoking now, you can slow the progression of cataracts.
Studies have shown that certain vitamins and nutrients may reduce age-related decline in eye health, particularly antioxidants. If you’ve already been diagnosed with cataracts, adding foods rich in antioxidants to your diet will help slow the progression. This list isn’t exhaustive, but here are some examples to get you started: dark chocolate, blueberries, strawberries, pecans, carrots, sweet potatoes, artichokes, kale, red cabbage, beans, beets, spinach, apples, and plums.
Doctors also recommend eating more fish high in omega-3 fatty acids. This has been linked to a potentially reduced risk of cataracts or their progression. You may also consider taking a multivitamin that contains Vitamin C and E. Talk to your doctor or nutritionist about how you might adopt a healthy eating plan that’s designed to prevent cataracts.
Fortunately, making these healthy modifications to your diet can prevent many other lifestyle diseases such as diabetes. Studies have shown that a diet rich in processed carbohydrates can increase your risk of both developing cataracts and speeding up its progression. It’s important to develop a plan that works for you and supports your holistic health.
Take control of your cataract diagnosis by getting regular eye exams, communicating with your doctor, and putting these tips into practice. You’ll have better vision and prevent the need for cataract surgery in the near future.
A refraction test also called a vision test, is usually performed as a part of a routine eye examination. The purpose of this test is to determine if a person has a refractive error which would then mean the patient would need glasses or contact lenses.
A value of 20/20 is normal (optimum) vision. This means that individuals who have 20/20 vision are able to read letters that are 3/8-inch (1 centimeter) tall from 20 feet (6 meters) away. The normal uncorrected vision (without glasses or contact lenses) refractive error is zero (Plano). Individuals who don’t have 20/20 vision, have what is called a refractive error. A refractive error means that the light is not bending properly when it passes through the lens of the eye. The refraction test will tell the doctor what prescription lens should be used in order to have a 20/20 vision.
For people over age 40 who have normal distance vision but difficulty with near vision, a refraction test with a small type size is used to determine normal near vision and the correct power of reading glasses.
The test is performed by having the patient seated in a chair that has a special device (called a phoropter or refractor) attached to it. The patient looks through the device and focuses on an eye chart 20 feet (6 meters) away. The device contains lenses of different strengths that can be moved into the patient’s view. The test is performed one eye at a time. If the patient is wearing contact lenses, they should be removed before the test.
In case the final vision is less than 20/20 even with lenses, then there is probably another non-optical problem with the eye. The vision level achieved during the refraction test is called the best-corrected visual acuity (BCVA).
Abnormal results may be due to:
Astigmatism (abnormally curved cornea causing blurred vision)
Presbyopia (inability to focus on near objects that develop with age)
Other conditions under which the test may be performed:
Corneal ulcers and infections
Loss of sharp vision due to macular degeneration
Retinal detachment (separation of the light-sensitive membrane (retina) in the back of the eye from its supporting layers)
Retinal vessel occlusion (blockage in a small artery that carries blood to the retina)
Retinitis pigmentosa (an inherited disorder of the retina)
There is an art to refraction and the optometrist will always answer the patient’s questions and as well as discuss their findings. Based on the results of the refraction test, they can determine the amount of myopia, hyperopia or astigmatism.