Ask the LASIK Surgeon
Do you have a question about LASIK? Use the form below to send it to Dr. Andrew Caster.
Dr. Caster dedicates his practice Caster Eye Center in Beverly Hills, Calif. exclusively to laser vision correction. He has been chosen by Los Angeles Magazine as the "Best Laser Eye Surgeon in Los Angeles," chosen by W Magazine as one of two top LASIK surgeons in the United States and voted by other physicians as one of the "Best Doctors in America." He is well known throughout the United States for his achievements in LASIK treatment and has performed more than 30,000 laser vision correction procedures.
Each week Dr. Caster will choose the best questions about LASIK to answer, which will be published on this page. Please remember that some questions can't be answered unless an eye doctor sees your eyes in person.
Please note that only pre-LASIK surgery questions will be considered. If you've already had LASIK and have questions please consult your surgeon. Before submitting your question please review the archived Q&A below to see if your question has already been answered.
To find the Q&As most helpful to you, please click on one of these subjects:
- LASIK and High Myopia, Hyperopia or Astigmatism
- LASIK and Age Limitations
- LASIK and Eye Conditions
- LASIK and Presbyopia
- LASIK After Other Eye Procedures, Including Laser Eye Surgery and Cataract Surgery
- Laser Eye Surgery and Pregnancy
- LASIK and Higher Order Aberrations
- Preparing for LASIK
- During the LASIK Procedure
- LASIK Risks and Complications
- PRK Laser Eye Surgery
LASIK and High Myopia, Hyperopia or Astigmatism
A: Laser vision correction is not appropriate for all refractive errors, and doctors differ in what they consider the maximum amount of myopia, or nearsightedness, that should be treated.
Some doctors consider -8 D to be the maximum, but in the United States the FDA has approved LASIK to treat up to -12 D.
Some patients with myopia of -10.5 D may choose to have an implantable lens (known as a phakic IOL) placed inside their eye as an alternative to LASIK.
The same complications are possible for a -10.5 D myope as for any other patient undergoing LASIK surgery. However, there will be a higher chance of needing a LASIK enhancement a second, fine-tuning procedure to obtain the best possible vision. Dr. Caster
Q: I have hyperopia (farsightedness) of +6.5 D in my right eye and +7 D in my left eye. Also, I have a "lazy" left eye from childhood. Can you advise whether I'd be a suitable candidate for LASIK surgery? And does my lazy eye prevent the surgery? S.
A: I would advise against having LASIK surgery in your particular situation. The maximum amount of hyperopia that is approved for LASIK treatment by the FDA is +6 D, but many doctors choose +3 or +4 D as the maximum they treat. Some of the laser machines are a little better than others at treating the +4 to +6 range.
Depending on your age, refractive lens exchange, or clear lens replacement, may be a suitable surgical alternative.
Lazy eye, referred to medically as amblyopia, can prevent a person from being a LASIK candidate, but it depends on the degree of "laziness." Dr. Caster
Q: I have farsightedness, with +6.5 D in my left eye and +2.0 D in my right eye. The research I've done up till now says that I am not a candidate for LASIK. I want your expert opinion on that. Is there any kind of laser surgery that can treat +6.5 D and help me get rid of glasses? A.
A: A prescription of +6.5 D is beyond the range that can be corrected with LASIK. For some people in this range of farsightedness, a clear lens extraction may be a viable option. I recommend that you look into that option. Dr. Caster
Q: I have worn glasses with a prescription of -7 D for the past 13 years. Would LASIK surgery be safe for me? My eye doctor has screened me for LASIK using the Allegretto wavefront-guided laser. I'm concerned that LASIK surgery may affect my professional life (I am a software engineer) and night vision. K.J.
A: Your situation is well within the range that the Allegretto technology system is used for, and with excellent results. Night vision can be adversely affected during the initial healing period (up to three months), but thereafter night vision is typically better than it was with glasses or contact lenses. Dr. Caster
Q: I am 20 years old and I have a high congenital myopia of -11 D. Am i a suitable candidate for LASIK surgery? Will I develop a cataract due to this surgery? J.
A: You may or may not be a candidate, depending on a host of other factors. A consultation is needed with your eye surgeon. Dr. Caster
Q: I have astigmatism. Can I still have LASIK surgery? T.
A: Yes, LASIK is very good at correcting astigmatism. Dr. Caster
Q: I have farsighted astigmatism in both eyes. My left eye is considerably better than my right eye; my right eye can't read very well unless the font is really large. Is this because of the astigmatism or something else?
If I were to get LASIK eye surgery, would my eyes be "balanced," i.e., would this bring my right eye up to the same level as my left? M.
A: If the right eye is healthy, correcting the farsighted astigmatism would improve the vision, presumably to the level of the other eye. Dr. Caster
Q: Can LASIK eye surgery correct astigmatism, or would eyeglasses still be needed? T.B.
A: LASIK corrects astigmatism. Most people who have LASIK have some astigmatism and they do not wear distance glasses or contact lenses afterwards. Dr. Caster
LASIK and Age Limitations
Q: I plan on having LASIK surgery when I turn 18, but I'm also enlisting in the Marines. Will my improved vision after LASIK be permanent? C.
A: LASIK does not stop the eyes from undergoing naturally occurring changes in the future. Most people who are nearsighted do not undergo much change after the age of 18, but some certainly do.
That is why most doctors will want the patient to have stable vision for one to two years before having LASIK, because those people are less likely to change afterward. If your eyes do change a little in the future, then you can have another LASIK treatment if you want to. Dr. Caster
Q: I have only been wearing glasses for two years. I am a 27-year-old female in active duty military. Would you recommend getting PRK or LASIK surgery so soon? L.H.
A: I would recommend waiting at least another two years, to be sure that your vision has stabilized. Dr. Caster
Q: Can you perform LASIK surgery on a 6-year-old child? What are the possible complications that may result? A.M.
A: Laser vision correction is now being used in younger children on a very limited basis only for certain specific medical reasons.
In general, it is not used in people less than the later teenage years or early 20s because vision often does not stabilize until that stage in life. The other issue with younger children is cooperation, both during the treatment and recovery period. Dr. Caster
Q: I am 15 years old and my eyes have been stable at -4.25 D (left) and -4.50 D (right) for the past three years. Am I a good candidate for LASIK? K.
A: I would recommend waiting until you are 18 years old, which is the age that the FDA has set as its minimum approved age. It is not necessary to follow the FDA approved age limit, but I think it is wise to wait. Dr. Caster
LASIK and Eye Conditions
Q: My son was diagnosed with amblyopia, or "lazy eye," at age 7. At no time has he dealt with strabismus (crossed eyes). He patched the affected eye with some improvement, but his vision is still far less than his better eye.
We are investigating LASIK options for him. Is it possible to have a general idea of how effective the outcome of the surgery will be prior to committing to it? K.M.
A: LASIK can correct the amblyopic eye to the same degree that glasses or contacts can correct the vision. Dr. Caster
Q: I was born with crossed eyes, and had corrective surgery when i was 18 months old. I've had to wear glasses all my life and I cannot see very well past four to five feet in front of me, besides shapes and blurs. I cannot wear contacts, mainly because I was told I am very sensitive to light, so I have had to wear tinted glasses.
I was thinking of getting LASIK surgery, but not sure I could due to my corrective surgery when I was younger and the severe sensitivity to light i have now. Is it still possible I could have the surgery and it would help my vision and the sensitivity to light? I.M.
A: LASIK would not help your sensitivity to light, but could probably help your vision. An examination by a LASIK specialist is needed. Dr. Caster
Q: I have a lazy eye, and my right eye drifts inwards a bit when I don't wear contact lenses or glasses. Would having LASIK eye surgery produce the same results as wearing glasses or contacts, i.e., no drifting of the right eye occurring? K.M.
A: The eye alignment after LASIK would be similar to the alignment with contacts. Glasses sometimes have prism built into them, which can change the eye alignment in a way that contacts or LASIK do not. Dr. Caster
Q: I've been told I have a scar on my retina. Can LASIK fix the problem with my vision in that eye? I wear glasses, but only need them for the one eye. Would I still need to wear glasses? L.H.
A: LASIK will not repair the scar in the retina, but it can eliminate the need for glasses. I would only recommend LASIK if both eyes with glasses are capable of seeing quite well. Dr. Caster
Q: I have worn contact lenses for years. About two years ago I was diagnosed with blepharitis. Is it ever possible to have LASIK surgery with this condition? Is there a permanent cure for blepharitis? S.M.
A: Blepharitis is not a serious condition. It is sort of like dandruff, which can be an annoyance but is not particularly harmful. There is no cure; it comes and goes over time. But you can certainly still have LASIK surgery. Dr. Caster
Q: I've had several cosmetic eye procedures. I was told I have dry eyes, and scar tissue as a result of the dryness. My vision hasn't been worsened by this. Can I still have LASIK surgery? My wish is to not ever wear glasses again. A.E.
A: People with dry eyes can have laser vision correction. Sometimes, the non-flap version is preferable. If dryness is truly severe, no treatment is advised. However, the dryness is often better after laser vision correction than it was with contact lenses, which accentuate dryness. Dr. Caster
Q: If there is a history of glaucoma (mother/aunt/uncle) in my family, is it better for me to have PRK over LASIK surgery, in case I develop glaucoma myself as I get older? M.
A: Neither LASIK nor PRK will impact your development of glaucoma, nor will it influence the treatment of glaucoma. So choose whichever you prefer LASIK or PRK based on other factors. Dr. Caster
Q: I have type 1 diabetes, which is managed with an insulin pump. I know diabetics typically are not candidates for LASIK because of slower healing, but I tend to heal a lot faster than normal, at least with piercings and tattoos. Could it still be possible for me to get LASIK done? H.
A: Many LASIK surgeons will not treat patients with type 1 diabetes. Many others, however, do feel comfortable if the diabetes is well controlled and if there are no significant complications from the diabetes. Dr. Caster
LASIK and Presbyopia
Q: I have 20/20 distance vision but need reading glasses to for up-close tasks. I was told if I get LASIK to correct my near vision, I will have to wear glasses to see far because the corrective surgery will affect my distance vision. Is that true? D.F.
A: That is correct, if you adjust both eyes for reading. However, many people choose blended monovision, in which one eye is adjusted for near vision and one for far (either using contact lenses or laser correction).
This seems strange to many when they first hear about it, but it works very well for a significant portion of the reading glass population. A simple test by your LASIK doctor can determine if this would be right for you. Dr. Caster
Q: I am a 45-year-old woman and underwent LASIK last week to correct my vision (-4.75 D in both eyes). I was able to read and do computer work without glasses before the operation. Now, I have to use +1.50 D glasses for reading and computer work.
I don't want to wear reading glasses. Is there any remedy available, or can I get LASIK again to correct my near vision? H.M.
A: It is too soon to know what your reading vision will be. The near vision after LASIK should end up to be similar to the near vision with your distance glasses on, assuming both eyes were corrected for distance with LASIK. If you are interested in monovision blended vision, you can have one eye adjusted for near and one for far. Dr. Caster
Q: I'm a 57-year-old male in very good health and now wearing -9.00 D (Acuvue Oasis) contact lenses in both eyes. My vision has been very stable for years. I have very mild astigmatism in one eye but not enough to require a contact lens for astigmatism.
I'm considering LASIK surgery, but am concerned that if my eyesight should worsen as I get older I may not be able to have the surgery performed. If my eyesight should worsen, is it still possible to have LASIK performed with the intent to: 1) reduce the power magnification needed of my contact lenses; and 2) to see better when not wearing contact lenses? M.
A: Several factors, such as your corneal thickness, are important. If your corneas are of normal or greater thickness, you should be able to get your eyes corrected with LASIK and not need contact lenses or distance glasses. You will need reading glasses, unless you choose the monovision LASIK option. Dr. Caster
LASIK After Other Eye Procedures, Including Laser Eye Surgery and Cataract Surgery
A: It is certainly possible to have additional "enhancement" laser eye surgery a second, or if needed, a third time. Dr. Caster
Q: I had RK (radial kerotomy) surgery in 1992. It was very successful, however, in the past year or so I have noticed that my distance vision is poorer in the mornings when I wake. And if I lay down during the day, my vision is poorer when I get up.
Is this a result of RK? Is there anything I can do about it? Can you have LASIK to correct this? D.W.
A: RK, or LASIK for that matter, will not stop the eyes from changing over time. So it is possible that your eyes have changed a little since your original surgery. Fortunately, this can usually be corrected with a LASIK treatment, or with glasses or contacts lenses. Dr. Caster
Q: I had RK in 1993, two surgeries on my right eye and one on the left. In 2004, I had LASIK and it was fine for awhile but my vision has drifted some. Is it safe for me to have another procedure? M.K.
A: The answer is yes, it is probably safe. However, I would recommend that any further treatments be performed on the surface of the eye using PRK laser eye surgery. Your vision will probably continue to drift as a result of the RK treatment. Dr. Caster
Q: I had RK surgery in 1995 and it worked great. As I got older, I needed glasses for reading and have had to revert back to glasses. I have heard that I cannot have any more eye surgeries to correct my eye problems now. Is this true? Can I have eye surgery and correct my vision so I do not have to have glasses? If so, what type of eye surgery am I looking for? B.H.
A: What you have heard is completely wrong. Laser vision correction can be used for people who have had RK. You can choose to have both eyes corrected for distance. If you are over 45, you will need up-close reading glasses. If you are over 45 you may choose to have blended monovision, in which one eye is adjusted for distance and the other for up-close reading. This is based on your desires and testing at the doctor's office. Dr. Caster
Q: I had RK about 25 years ago, but now my vision is starting to blur distance, close up and computer work). Could I be a candidate for LASIK correction now? C.G.
A: Yes. People who had RK in the past can typically have laser vision correction if their eyes have changed over the years. Dr. Caster
Q: If my vision changes after LASIK surgery, can the procedure be performed again? Basically, how many times can surgery be performed if vision keeps changing? J.R.
A: LASIK surgery can almost always be performed again if your eyes change in the future. There is really no limit if there is enough thickness to the cornea. Dr. Caster
Q: I would like to know if you can have LASIK performed more than once. Back in 1999 I had it done and it was wonderful. But about three years later my eyes went bad again. I was thinking about doing it again, but will the results last longer than three years? I am 60 years of age. B.R.
A: Laser vision correction can typically be performed more than once, if needed. Of course, laser vision correction does not stop your eyes from naturally occurring changes such as presbyopia. Dr. Caster
Q: What are the increased risks of having LASIK performed a third time? My mother has had LASIK twice and now needs to go again for a third time. C.C.
A: The risks from a third procedure are no greater, or less, than the risks from the second procedure.
These include infection, epithelial ingrowth (which would require an additional but minor treatment), and problems with the flap. Overall, the chances of a problem are quite low and can be usually easily treated. Dr. Caster
Q: Can you have LASIK surgery for vision correction after having cataract surgery? B.H.
A: Yes, LASIK is often performed after cataract surgery. Dr. Caster
Q: I had bilateral eye surgery when I was 13 years old. Can I still get LASIK? L.
A: Well, it depends on what type of surgery you had. Most likely, you had surgery to straighten your eyes to correct a condition called strabismus (crossed eyes). If so, the answer is yes! Dr. Caster
Q: My son had laser surgery on his eyes when he was one month old for retinopathy due to prematurity. Now he has vision that can only be corrected to 20/40 with glasses and he wants to go into law enforcement. Is he a candidate for LASIK eye surgery? C.K.
A: I would advise against laser eye surgery in this situation. Also, typically with vision corrected to, at best, 20/40 with glasses, he would not qualify for law enforcement even if he had laser eye treatment. Dr. Caster
Laser Eye Surgery and Pregnancy
Q: I just found out I'm four weeks pregnant and have PRK scheduled for next week. Is it safe for my baby to continue with the surgery? All pre-op is completed. T.S.
A: I would wait until after the baby is born and after you have stopped nursing. Although all the drops and pills used are most likely safe for the baby, it is always better to be cautious and avoid medications that can be avoided in this case, by postponing your treatment. Dr. Caster
Q: I've heard that it's better to have vision correction surgery (LASIK, etc.) after pregnancy because your eyeglass prescription may change. Since I'm planning to become pregnant soon (maybe in six months' time), I'd like to know if it's better to wait until having the baby or if there is no difference at all? Z.E.
A: It is possible for the hormones associated with pregnancy and breast-feeding to change your glasses prescription. Most likely, however, this would be on a temporary basis, because the hormones are temporary.
I have been performing vision correction surgery for a long time, and I cannot remember even a single patient whose prescription changed a significant amount on a permanent basis as a result of pregnancy.
So my advice is: Do not have LASIK surgery if you are pregnant or breast-feeding. But it is okay to have the procedure now, even if you plan to be pregnant in the future. Dr. Caster
Q: Is it true that a woman must wait until she has finished having kids and nursing before getting LASIK surgery? G.W.
A: This is a common misperception. A woman does not have to wait until after having children.
This misperception occurs because of the following: there is a very small percentage of women who will have their prescription change a little bit, usually temporarily, while pregnant or breast-feeding. After the pregnancy and breast-feeding are over, the prescription almost all the time returns to where it was before the pregnancy.
So it is advisable not to have laser vision correction if you are pregnant or breast-feeding, but it is fine before or afterwards. Dr. Caster
LASIK and Higher Order Aberrations
Q: I have nearsightedness (4.5 and 5.5 D) and astigmatism and have been told that I am a good candidate for all-laser LASIK. I currently see big starbursts around light sources at night while wearing glasses, such as oncoming headlights while driving.
Does the fact that I already have this issue prior to getting LASIK mean that it is more likely that I am going to experience worse or longer lasting starbursts after LASIK?
The clinic that qualified me for LASIK is telling me that none of their patients ever have starbursts for more than 90 days after the procedure since it is all about correct laser calibration and technique, but then I read so many stories about people who have this problem for years or forever. A.
A: The newer technologies will in most cases not make the pre-existing starbursts worse, but they also are unlikely to make them better than they are with your glasses. So you will probably continue to have starbursts after LASIK, most likely similar to how they are now with your glasses.
During the first 90 days they may be worse than you are used to, but they will then most likely revert to your current level of starbursts. Dr. Caster
Q: When I was 17 years old I was hit in the eye with a paintball, which caused scarring to my retina. I currently have some "black spots" where i see nothing, but this doesn't bother me as much as the blurry vision I experience.
Is it possible that LASIK could help smooth the affected areas of my eye so I can see clearly again through my damaged eye? M.D.
A: Unfortunately, LASIK surgery is not able to adjust for scarring problems with the retina. Dr. Caster
Q: Does requiring prism in my glasses make me a bad candidate for LASIK? R.D.
A: If you need prism now, you will need prism after LASIK. Prism cannot be corrected with contact lenses or LASIK, only with glasses. Dr. Caster
Preparing for LASIK
Q: I have been using contact lenses for the past six years. I want to get LASIK, and my sight has stabilized. So how long before the LASIK procedure should I stop wearing contacts? A.K.
A: It depends on what type of contact lens you are using. For regular soft lenses, three to seven days is recommended (different doctors choose different guidelines). For gas-permeable lenses, usually two months is needed. Dr. Caster
During the LASIK Procedure
Q: Can you have LASIK eye surgery under sedation? I have a very big fear of anything going near my eyes and have never even been able to put contact lenses in. E.F.
A: Fear of things near the eyes and difficulty with putting in contact lenses are very common. In fact, this is one of the most common reasons people undergo LASIK because they cannot wear contact lenses and do not want to wear eyeglasses.
Most patients are sedated when they have LASIK treatment. Sedative medications will not put you to sleep, but they will help eliminiate anxiety and make you will feel much calmer and at ease. Sedation makes the LASIK process pretty easy for the patient, even for those who have this common fear. Dr. Caster
Q: Does the patient have to be awake during LASIK surgery? B.B.
A: Yes. But your eye doctor may give you medication beforehand to help you relax, which makes the whole process quite easy. Dr. Caster
LASIK Risks and Complications
Q: Does LASIK have any long-term complications? E.A.E.
A: Generally, the only significant long-term complication of LASIK is a change in refraction. That is, some people will become nearsighted, farsighted, or astigmatic to a small degree some years after treatment.
LASIK does not stop the eyes from changing. But if there is a change in vision, the degree of nearsightedness, farsightedness or astigmatism will be much less than the original amount, and can typically be corrected with an "enhancement" LASIK treatment. Dr. Caster
PRK Laser Eye Surgery
Q: How safe is PRK surgery after LASIK? I have had three unsuccessful LASIK procedures and now my doctor is suggesting PRK. P.
A: PRK is often performed as an enhancement to LASIK treatment, especially after several flap-lift treatments that have not resulted in total correction of vision. There are no guarantees of total perfection, but the procedure is very safe and usually gets the job done. The healing process, however, is slower than with LASIK. Dr. Caster
Q: The navy will pay for my LASIK or PRK surgery. I want to be a pilot, and someone told me LASIK disqualifies you for flying. My eyes are approved for both LASIK and PRK, and I was wondering which one would be better for me becoming a pilot. I am 19, my prescription lens glasses haven't changed since I was 16. I am an active duty corpsman, aka combat medic. B.A
A: You will get the same result from LASIK or PRK. My understanding is that the military is now happy with both LASIK and PRK, but each branch sets its own policy and you should check with the navy to be 100 percent certain. Dr. Caster
Q: I would like to ask if there are any existing tests or procedures that can be done to examine if laser surgery has been conducted on an individual. In other words, is it possible to find out if someone has had laser surgery if there are no official paper records? B.
A: There are tests that will frequently, but not always, identify a person who has had laser vision correction. If the correction was very small, the tests may not show the treatment. Dr. Caster
[Page updated May 2013]
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