Light Adjustable Lens EDOF is not testable, not reversible
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I asked my doctor today about using the light adjustable lens in my left eye, with the extended depth of focus added by manipulating its spherical aberrations. He said "I love the LAL. It helps us hit your refractive targets and we can add EDOF to it." Then I asked, if the EDOF can be tried, tweaked if it's not just right, or removed if the patient does not like it, before the lens if locked. He said no. EDOF is only added in the last session and then the lens is locked. The sphere and cylinder can be played with in multiple sessions, but you buy the EDOF feature blind, so to speak. That's too bad, because obviously there is a loss of contrast sensitivity and ideally you would get to experience that and then decide whether the EDOF is worth the cost in terms of lost contrast sensitivity.
3 likes, 4 replies
julie66167 jimluck
Edited
jimluck,
I was just thinking of you and the 2015 article you posted a few weeks back on EDOF - Light Adjustable lens and loss of contrast sensitivity. You mentioned how much EDOF was used in those 20 eyes. Alot. This is from memory so please correct if I my memory is not correct.
I was also told by my ophthalmologist's top tech that EDOF can't be reversed but "why would you want to"? Loss of contrast sensitivity can't be corrected with glasses! Did your doctor mention how many diopters is used for the EDOF ? Does the patient choose where it is placed - near or intermediate?
RonAKA jimluck
Edited
I think the LAL is a bit of a black box. I have seen no clinical studies on the EDOF feature of the lens. From what I can gather they are adjusting the asphericity of the lens to stretch the focal point to give the EDOF. This is a matter of adjusting the power of the lens from the center out to the edge so it is not uniform. It would strike me that this should be reversible if the complete lens can be adjusted with the UV. Perhaps it is not. They also talk about adding negative asphericity to the lens when it is actually positive asphericity that is typically used to extend the depth of focus.
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This said the ability of the lens to be adjusted for power in the eye, and the ability to adjust for astigmatism is a great feature. It allow on to test drive different amounts of monovision and change your mind if you do not like it. Those are great features, but I think I would pass on the EDOF option, assuming it is optional...
jimluck RonAKA
Edited
It's optional.
RonAKA jimluck
Edited
I would decline then. With standard mini-monovision, EDOF is an unnecessary feature.