My prescription glasses are +2.5 for farsightedness (hyperopia) on either side with some astigmatism in the left eye. Due to rigidity after strabismus surgery I have lagging eye movements and some degree of both divergence and convergence insufficiency.
What are the effects of those glasses?
Close range work / reading
—> Helps with accommodation, in other words seeing a clear image.
—> Counter-acts convergence, makes the eyes slide outwards/diverge.
—> Makes convergence insufficiency worse.
—> Doubling of the images.
Beyond 1,5 meter range
—> Helps the eyes diverge.
—> Helps to execute the needed divergent movement.
—> Helps manage fatigue and largely avoids double vision.
—> Counter-acts accommodation, blurs images further away resulting in less acuity.
—> Have to look over the frame of my specticles to see/read details.
How do I use them in practice?
Close range work/reading
– Generally I don’t wear glasses when doing close-up computer or reading work. The vergence disadvantage of the glasses is greater than the accommodation advantage. The result is that reading/close range work is not sustainable for long periods of time, both with or without glasses. This is true for desk work but also for close range manual labour.
Beyond 1,5 meter range
– Generally I do wear the glasses. The vergence advantage of the spectacles is greater than the accommodation disadvantage (blurry vision). Even with the vergence advantage of the glasses, divergence is still laboured and accurate performance is not sustainable for longer periods. This limits driving time but also other forms of mobility due to secondary effects such as nausea and dizziness.
– The plus lenses in my glasses are usually used for help with reading, aka reading glasses. Due to vergence difficulties I effectively use them the other way around which is a bit absurd.
– Vergence (divergence as well as convergence) is still the weakest link in the mechanics of my vision and my visual system as a whole.
– The glasses do have a limited effect on vergence but not enough to completely resolve functional issues. Ultimately this function should be performed with more ease and consistency by the organism itself without this tool.
– Glasses can be a tool to increase comfort up to some point but will not be a remedy for serious eye movement and functional vision ailments. Structural training, stretching and automation of movement is crucial.
– Given my history, including various eye muscle surgeries, and past progress, smooth vergence/eye movement without excessive rigidity might still take a while.
Remarks / further testing
– Would contacts be beneficial in resolving some of these accommodation/vergence conflicts?