I’ve been wearing varifocal glasses for a number of years. Recently I’ve noticed some difficulty reading in the evenings and and thought I needed my prescription required strengthening.
I went for an eye test at Boots last week as I highly rate their optician service. The optician told me that my prescription had not changed in 2 years. He believes that due to my Parkinson’s, as my eye muscles get tired at the end of the day they are struggling to focus and has recommended that a +1 Prism is added to my prescription. He believes this will help in the evenings although during the day when I can better focus it may be to the detriment of my vision.
I think he was referring to the muscles that move my eyeballs, not the muscles that change the shape of the lenses.
Has anyone else been recommended a prism in their lenses.
As a side note, I do suffer with sore/dry eyes especially when concentrating all day on a computer screen due to my slower blink rate. To help I use Hycosan eye drops several times a day. These drops help lubricate the eyes and work well for me.
I use prisms, but they are for double vision. I never heard of them being recommended for tired eyes. I also have some difficulty reading in the evening. My eye professional said that the dry-eye condition causes vision to be unclear at times. For me, that means evenings because I am not as careful in using my eye drops then.
Hi Mark
I am a retired Optometrist (64, diagnosed in 2015)and use prisms in my specs. The problem that is being helped by prisms is slight misalignment of the eyes. A small misalignment gives tired eyes and headaches, slightly greater can give double vision. The position of the eyes in their bony sockets are controlled by 6 small muscles for each eye. Often, at rest eyes do not point at the same thing and then double vision can occur. If the mis-pointing is not too severe, the eyes just feel tired and you can get headaches, gritty eyes, etc.
The prisms bend light (remember the Pink Floyd album cover!) and this helps the eyes stay in alignment. When you are fresh, you can probably maintain eye alignment without additional help but when you are tired or under the weather the system struggles and the prisms help.
One thing that can sometimes cause problems with varifocals (or bifocals) is if the amount of prism differs with distance (TV and driving) prescription and near (reading, model making etc) needing to have different amounts of prism. In this case you might be advised to have two pairs of specs for different tasks.
As fatigue is part of Parkinson’s this is just another of the things sent to try us. Mind you, the misalignment happens to many non-Parkinson’s as well.
Hope you can make sense of my explanation.
Regards
Thorny
I have a similar problem in the evening wearing varifocals and have helped the problem by having a pair of reading glasses. As I have a laptop with a relatively small screen I use them for computer work too which I find is less strain on my eyes.
