Main Page / Login Option Forums Community Forum Confusion: optometrists prescription lower than my measurements

Answered
  • Creator
    Topic
  • #79199
    Sophie Mercado
    Participant
    Post count: 4

    Sorry if this is sending twice. Couldn’t see if it had sent so copied….

    As the title says, I’m really confused. I had an eye test done 21/9/22 and this was the result.

    R: -3.00 Cyl: -0.75 Axix: 170
    L: -2.50 Cyl: -0.25

    I explained in the test that I get strain when things are really clear and that I wanted to be at the lower end. I think he has taken it to the extreme. He said I would be insured to drive with this prescription. I went today to get some contacts to try out which are these and are so low:
    R: -2.5 / -0.75 x 170 (Toric lense)
    L: -2.0

    When I came out of the optician and walked to my car I thought I was going to fall over. I felt so dizzy. Is this normal with a Toric lense. Is it essential to have for cylinder of 0.75. When I got home I looked at my snellen (it’s not the best. A bit dark in my kitchen at that time and also the home print quality isn’t the best but I’m using it while I wait for a professional one to arrive. But basically, I couldn’t see 20/40 on this chart. I have been wearing:
    R: -3.5
    L: -3.0
    I could see more than 20/20 so I knew I needed to go down but the jump seems huge.
    I really want to get glasses and don’t know what to use. My measurements are so much higher than the opticians (see below). He has tried to accommodate the fact I get eye strain when contacts are too strong or during the eye test when the letters are clearer, I get a strain around the inner canthus and eye lids of my eye. So because of this and because I said I wanted to be on the lower end (silly move on my part perhaps) I have this crazy prescription and don’t know where to go from here.

    This is so low compared to my eye measuring. The range for my eye measuring is:
    R: -3.3 to 4.1 (this was after a long evening of research on my laptop and phone)
    L: -2.9 to -3.4

    Using Snellen, I could read 20/20 and could kind of read the line below wearing -3.5/-3.0 contacts.

    Last July me prescription was:
    R: -3.75 Cyl: -0.5
    L: -3.5 Cyl: -0.25
    I never got glasses and got contacts online based on trial and error as the opto suggested a weird combination.

    I really don’t know what to do. I have 5 days of contacts to try out but I had to get them out the minute I got home as I couldn’t bear them so not sure how I’ll get on tomorrow. I have these, a few pairs of my -3.0 and -3.5 and a pair of 10 year old glasses that are way too strong (circa -4.0/-3.75 I think). I lost 2 weeks of eye measurements when my phone was stolen and would like to have a couple more weeks of measurements but I need to do something quickly or I’ll have nothing to wear. Not sure what to order.

    Any thoughts. I know differentials are usually the first thing to get but I don’t actually have normalised contacts or glasses, other than my -3.5/-3.25 contacts which I think were too strong based on Snellen.
    Also if I end up ordering my contacts online, is it essential to get the -0.75 cyc. I’ve not been wearing any with a cyl measurement and the way it made me feel (I get vertigo and it was like that), I really would rather avoid.

    Sorry this is so long. I know asking about diopters is a no-no but I feel like my situation is a bit confusing/messed up.
    Thank you, Sophie

Viewing 6 reply threads
  • Author
    Replies
    • Jake S.
      Keymaster
      Post count: 8756

      Hi Sophie,

      First question: Why the giant drop in distance glasses?

      You can always ask about diopters here.

      Are you following the course? Note that it is absolutely important to follow the sessions exactly. I can only provide support for the course, if you opt to make random changes to your glasses otherwise, I can’t tell you what the outcomes might be.

      I very strongly recommend NOT messing with changing diopters till you know why, and what. It is very counterproductive to make unplanned changes. Your visual cortex will be confused, additional changes may yield unexpected outcomes.

      Differentials are first.

    • Sophie Mercado
      Participant
      Post count: 4

      Thank Jake. Yes I’m following the course, albeit only at lesson 9 but have completed the measuring course and have also read the wiki pages and watched lots of your YT videos.

      Unfortunately, I’ve been kind of guessing diometers for my contacts for 15 months, with trial and error, as I didn’t agree with the monovision prescription the opto gave in July 21 to have 1 eye undercorrected and 1 overcorrected. I just ordered a selection of contacts and tried what was best, testing my eyes with number plates and things around the home. My glasses are from 10+ years ago and I don’t even know the prescription. I know they over correct from my Snellen chart.

      My diopter dropped in my last 2 eye tests weirdly. But I think the massive drop this time is because I stressed I didn’t want to be overcorrected because sharp vision/clarity often hurts around my eyes in the eye test (probably actually overcorrection) and he understood that I wanted to have a lower prescription. I just didn’t want to be that far from 20/20. I don’t know why the contacts the opto has given are even lower than the prescription he gave. I thought you don’t have ajust down for contacts once below -3.5
      ish.

      What is confusing me is my own measurements are so far from the optometrist’s prescription so I don’t know what to believe or work from. I don’t think I’m doing it wrong as I measure just at the point where sharp clarity stops. My average measurements work out as diopters above the contacts I’ve been wearing but these contacts give me 20/20 on a 3 metre snellen and I can read about half of the line below. I have to order something today, at least just some contacts, to keep me going as I’m nearly out of contacts and only wear the old scratched glasses at home. I will have to guess unfortunately as I don’t feel I have a reliable starting point from the optometrist and I know that with my measurements would point to higher than I’m currently wearing. I’ve been measuring for nearly 4 weeks now but only have nearly 2 weeks of those measurements. With -3.5/-3.0 I can just about read the line below 20/20 so I will take it that these are slightly too strong and maybe drop -0.25. But I don’t know if I need to get a toric lense.

      Given I have no reliable starting point to know what a normalised lense/contact is, at what stage of the course would someone normally have enough information to order glasses.
      Thanks, Sophie

    • Jake S.
      Keymaster
      Post count: 8756

      Understood. Thanks for clarifying (again), I do sometimes get a bit lost on the exact details and history if I’m not looking at the latest posts. Apologies!

      A big thing to untangle indeed would be the monovision. There’s no definitive guaranteed way to do it other than to adjust diopters accordingly for binocular vision, and see how the eyes adapt to it. You want to avoid strain, headaches, etc. Some people just snap back and are good with a nice binocular (both eyes working together) correction, others take more steps to get there.

      One major thing, if you can see without double vision or ghosting without cylinder, definitely avoid cylinder. It’s better to have a bit more spherical if that compensates for any slight astigmatism symptom, than to add cylinder. Especially in contact lenses that’s just another level of complexity that you want to avoid if reasonably feasible.

      It does seem that around -3 would work. The simpler the correction, the better. You might be able to get some sample contact lenses if need be (you did say you were experimenting already).

      Then you want to just keep those the same for a few months, make sure eyes and brain fully adapt that correction.

    • Jake S.
      Keymaster
      Post count: 8756

      Understood. Thanks for clarifying (again), I do sometimes get a bit lost on the exact details and history if I’m not looking at the latest posts. Apologies!

      A big thing to untangle indeed would be the monovision. There’s no definitive guaranteed way to do it other than to adjust diopters accordingly for binocular vision, and see how the eyes adapt to it. You want to avoid strain, headaches, etc. Some people just snap back and are good with a nice binocular (both eyes working together) correction, others take more steps to get there.

      One major thing, if you can see without double vision or ghosting without cylinder, definitely avoid cylinder. It’s better to have a bit more spherical if that compensates for any slight astigmatism symptom, than to add cylinder. Especially in contact lenses that’s just another level of complexity that you want to avoid if reasonably feasible.

      It does seem that around -3 would work. The simpler the correction, the better. You might be able to get some sample contact lenses if need be (you did say you were experimenting already).

      Then you want to just keep those the same for a few months, make sure eyes and brain fully adapt that correction.

    • Sophie Mercado
      Participant
      Post count: 4

      Hi Jake

      Thanks for your message.
      I paid today for a second opinion eye test at a new place and got completely different result.

      He said full prescription would be:
      R: -4.0 /-0.5
      L: -3.25 / -0.25

      But he said this is better than 20/20 and I explained I didn’t want that and I found when it is better I get an ache on my eyelid/inner eye. He suggested going weaker and tried out how it was with 0.25, 0.5 and 0.75 weaker. 0.75 was much too weak but 0.5 and 0.25 weaker both seemed ok but -0.5 obvs more blurry on what he was testing me with.

      I’m just wondering now whether to go for
      R:-3.75 L:-3.0
      or
      R: -3.5 L: -2.75

      The first one matches my eye measurements more. Do you have a view on what would be best?

      Thank you.

    • Sophie Mercado
      Participant
      Post count: 4

      Also, just to add if it’s helpful, the average for the last 3 days of eye measurements work out to:
      R: -3.7
      L: -3.3

      The optometrist worked out a Rx which was 0.75 different in each eye but my measurements tend to be around 0.5 different.

      I’m going to buy normalised and differentials at the same time as the 10 year old glasses are -4.25 in the right eye.

    • Jake S.
      Keymaster
      Post count: 8756

      You have a lot of data there, and unlike me, first hand insight into how it was gathered – ie. your feedback while the exams were happening.

      Trust yourself!

      I’m happy to help when I can, mainly I provide support for the course. It’s quite iffy to change multiple focal planes at once, to be honest. Visual cortex tends to be far more challenged by not having a single familiar focal plane. It’s not really the course of the scope and falls into the territory of you having your own experiment going on a bit.

      It’s good for this to do as you did, and gather as much data from as many sources as possible. No single measurement is going to tell the full story, and vision varies quite a lot depending on lighting and external factors as well as strain levels, sleep, diet, stress.

Viewing 6 reply threads
  • You must be logged in to reply to this topic.