Friday, November 18, 2011

My Experience with CRT Contacts / Corneal Molding Lenses

I received my new CRT contacts today. CRT stands for Corneal Refractive Therapy which involves wearing gas-permeable hard contacts that mold the cornea of the eye while you sleep so you don't need to wear contacts during the day. My eye doctor first mentioned this treatment to me a couple years ago but I am finally trying it now.

At first, I didn't see the benefit since I would still have to wear contacts every day (only switching to night) but after weighing the pros I decided to try it instead of laser surgery. With CRT, I will now have good vision 24/7, no more red-eyes at the end of a long day, and no more problems with dust getting trapped under a lens or losing one in the water. Also, my normal vision is -5.25 diopters in my right eye and -2.5 in the left. This big difference makes it hard to read in bed or focus on my computer monitor after I take my regular contacts out for the night.

Since I've worn hard contacts for about 20 years, the doctor prescribed me soft contacts for a week so my eyes could return to their normal shape in order to take correct measurements for the new CRT contacts. After a few days, he discovered that I also had a mild astigmatism, hidden by the slight molding effect of my current hard contacts. After the week ended, he used a Willy Wonka-type device to measure the exact surface shape of my eyes. I had to stare wide-eyed down a brightly-lit tube filled with yellow and black stripes as the instrument beeped and booped.

Update: After almost three months, I have returned to my old hard contacts because I was not able to achieve optimal vision with the CRT contacts. The most likely cause is that I did not wear the transitional soft contacts long enough between my regular hard lenses and the measurement for my new CRT contacts. Below is my journal entries of the experience.

Day 1: 11/21/11 Monday

Since I went to Universal Studios this weekend, I waited until Sunday night to wear my CRT contacts for the first time. With my eyes closed, I can't feel them at all so I had no trouble sleeping with them last night. After removing them this morning, I was still able to wear my soft contacts with the original prescription, but I can already tell there is a difference since my vision is slightly distorted. It is harder to see close up, probably because the prescription is now too strong.

Day 2: 11/22/11 Tuesday

My vision has improved enough that the soft contacts with my original prescription are now too blurry to wear today. The only problem is the next lower step of temporary soft contacts are not quite strong enough. (Right -3.5 & Left -1.5) I can barely see my computer monitor at work. They told me I could experience some double vision early in this transition phase and I think that's what this is.

Day 3: 11/23/11 Wednesday

My eyes are still having issues focusing close-up with my -3.5 Right & -1.5 Left soft contacts, so I scheduled an appointment with my doctor before the Thanksgiving weekend started. Turns out that the nearsightedness was improving much quicker than my astigmatism (-1.5 in both) so the soft contacts he gave me weren't accurate anymore. I am now down to -1.5 in the right and -0.5 in the left. The other ones were causing me farsightedness. With these new temps in, I can now see my computer screen again. It's not perfect, but so much better. The doctor thinks I will soon be able to go without a soft contact in the left eye and he gave me a -0.5 as the next step down for my right.

Day 4: 11/24/11 Thanksgiving Day

Yesterday, the new soft contacts the doctor gave me were a little weak, but now they are perfect since my vision improved more overnight. Good thing too, since I am driving to my mother's house in Riverside today for Thanksgiving.

Day 5: 11/25/11 Friday

The Right -1.5 & Left -0.5 still work but I think they are now a little strong. I probably won't be able to wear them tomorrow.

Day 6: 11/26/11 Saturday

I wore the -0.5 in my right eye today and nothing in my left. The vision for both is still blurry, but the other pair is now too strong for close up viewing. At night, I put in the stronger pair so I could see my friend's TV better at a distance.

Day 7: 11/27/11 Sunday

They say that 90% of the vision change occurs after one week. That is true with the left eye. It is now really close to normal vision, but I still get a little blur. I think the nearsightedness may be completely adjusted but with a touch of astigmatism that still hasn't been corrected. I'm still a little blurry in the right eye with the -0.5 but I found if I get a lot of light, the vision can be pretty good.

Day 8: 11/28/11 Monday

Taking off the CRT contacts this morning, the difference was the smallest yet. My nearsightedness seems almost gone, but I still have some blurriness. I put in the -0.5 soft contact in my right eye again this morning, but it only improved the vision a tiny bit. I probably won't wear it tomorrow.

Day 9: 11/29/11 Tuesday

My right eye still needs the -0.5 soft contact while the left still has about the same level of blurriness. I am now pretty sure most of the remaining blur is from my astigmatism. My vision will get sharp if I keep my eyes focused on a set distance, but it's very slow to refocus when I look closer or further away. My doctor said last week that if these current CRT contacts don't correct the astigmatism, then he may need to make an adjustment to my CRT prescription. But it may just be that my corneas still need more time to stabilize since it can take two to three weeks to achieve optimum vision. I'll find out at my Thursday appointment if the problem with focusing is still hanging around.

Day 10: 11/30/11 Wednesday

Pretty much the same vision today. I can't tell any difference.

Day 11: 12/1/11 Thursday

The morning of my eye appointment, I noticed a big difference in my right eye after removing my CRT contacts. For the first time, the right had almost equal vision with the left. At the optometrist, my suspicions were confirmed that the remaining blurriness in my eyes was from astigmatism. The CRT contacts had taken away the nearsightedness but was still inducing astigmatism in both eyes. The doctor took new measurements of my eyes and is going to order a new pair to correct it. He gave me a new pair of soft contacts to wear until the new ones come in. They are plano lenses (-0.0) with a -0.25 adjustment for the astigmatism. While the left eye is perfect with the new lenses, the right is more blurry with it in even though it is the exact prescription. The doctor double-checked it but can't find the problem. I think it may be an effect from the overnight vision change in the eye. Maybe it will be better tomorrow.

Day 12: 12/2/11 Friday

The plano lens for my right eye is still blurry so I am wearing the -1.5 instead. It is a little too strong, but it corrects the astigmatism and doesn't make me too farsighted. Unless I experience some dramatic vision change, I won't write anymore daily entries until after I receive my new CRT contacts.

Day 17: 12/7/11 Wednesday

I was hoping I would have good news after the first night of wearing my new pair of CRT contacts, but the blurring effect of the astigmatism is still there. It may take more than one night to fix my vision so I will wait a couple days before I get disappointed.

Day 23: 12/13/11 Tuesday

My doctor confirmed at my appointment this morning that the second CRT pair has not improved the astigmatism. He's going to make some adjustments and order another set. While it will be worth it as soon as my vision is dialed in, this transition period of poor eyesight is very frustrating. At least for my right eye, he gave me a -1.0 soft contact to replace the -1.5 that was too strong. It's much better.

Day 33: 12/23/11 Friday

I got my new set of CRT contacts yesterday from a different manufacturer this time. For an accurate fit, they sent three contacts for each eye. While the first fit perfectly on the right eye, I had to try on all three to find the one that lay properly on my left. The doctor said it would take a few days until we know if these work better. This first day didn't show much improvement but I did notice that my vision with my soft contacts was slightly altered which is a good sign.

Day 34: 12/24/11 Saturday

There is definite progress today! At first I just recognized the usual blurriness, but then I noticed that I could actually read the graphics on my TV from the back of the room. I could not do that before. It was confirmed when I put in the soft contacts and the TV was harder to read, so I took them back out. I think these may be finally adjusting my astigmatism. :)

Day 37: 12/27/11 Tuesday

I may have spoke too soon. My vision may have increased a little bit but it quickly leveled off at the same level it was on Saturday. No further improvement since.

Day 39: 12/29/11 Thursday

I had another eye appointment today and the doctor confirmed my vision. The astigmatism is still there with this new pair even though my nearsightedness is corrected. While the temp contact can adjust for it in my left eye, the astigmatism is much worse in the right. If I wear a temp contact to adjust for it in my right, my vision actually worsens and drops to -3. The doctor suspects that the CRT is over-correcting in that eye and creating two focal points. He is going to talk with a consultant and order me a new pair of CRT contacts that correct this. He says if this final pair doesn't fix it, I may need to start over. Stop wearing the CRTs until my vision goes back to normal and than re-measure. A week may not have been enough time when I stop wearing my old hard contacts at the beginning of this process.

Day 52: 1/11/12 Wednesday

After a week of wearing my 4th set of CRT contacts with no noticeable vision changes, I am ready to call it quits. Starting over may work, but I am just too burn out on having blurry vision for almost two months. I really wanted this to work, but I am going to stop wearing the CRTs and in two weeks when my eyes have returned to their natural state, the doctor will remeasure for a regular pair of hard contacts. He told me that I am his first patient where the CRT contacts have not worked. In the future when he has a patient who has worn hard contacts for so long previously, he'll have them wear soft contacts for a month before measuring for the CRTs.

Day 56: 1/15/12 Sunday

I'm back to having clear vision again. After one night of not wearing the CRT contacts, I was able to put in the soft contacts with my original prescription today. To celebrate, I went to see a couple movies I've been wanting to see at the theater, "Hugo" in 3D and "Mission Impossible 4" in IMAX. Now I just have to get a new pair of my standard hard contacts and my experimentation in Corneal Molding with be complete.

Day 75: 2/3/12 Friday

I received my new hard contacts today so I am back where I originally started.


  1. Anonymous7:20 AM

    Thank you for your blog. I am researching and trying to decide whether to put my son through this. He's 9 with -4.0 prescription. He will probably grow up to be almost-blind. I've read that using CRT for a long time at this age may reduce his long-term change. He doesn't have a lot of patience, however, and your blog has given me plenty to think about. Thank you.

  2. Your welcome. If he has only worn glasses or soft contacts in the past, then I doubt he will have the same issues I experienced with CRT contacts.

  3. My daughter is having the same problem. She has been doing CRT for 4 months now and her nearsightedness is fixed but her astigmatism will not budge and I think it's actually getting worse. She only wore soft contact lenses before but she started with a -5.75 prescription and I think her astigmatism was pretty high -2.00 or something too. Doc is ordering yet again another new set but I don't know at what point you call it quits. She is willing to keep trying but I wonder if we will ever be done with this and find the right lens. She is now complaining of shadowing and double vision too.

    1. I am sorry to hear that. I wish CRT could have fixed my astigmatism because it was amazing to see clearly outside in the sun without contacts for the first time in my life. But the astigmatism blurred my vision as soon as my pupils dilated to adjust for dimmer lighting indoors or at night.

  4. Anonymous6:14 PM

    Does anyone have any experience with diabetes and this program