Round seg safety specs - UK

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12-01-2020, 08:57 AM
iLeeam

Round seg safety specs - UK

Hey guys, new to the forum so forgive me if this is in the wrong place etc. I've a patient who's a steel fabricator and hates the idea of progressive safety glasses. I've thought of a bif with Inter and Near as he needs a working distance of 70cm - 15cm. His distance rx is straight forward enough, (R: +0.75 / -1.00 and L: +1.25 / -0.75) so was thinking of an inter Add of +1.50 and segment add of a further +3.50. He's stationary once he's welding. Should I be taking anything else into account, such as differential prism? I've adapted the position of segment for convergence and assume a round seg would be easier to adapt to as it will have reduced image jump.

Once again, apologies if this is in the wrong place. Will gladly take any feedback or advice!
12-01-2020, 09:51 AM
Beeped

Has he had bifocals before? I think Hoya does 'invisible' round seg bifocals in poly, not sure about trivex. With a Franklin split you'd be able to achieve a lot more peripheral, if he can get used to the image jump. Does he do both welding overhead and below? Or just in front of him, say at reading distance/position? If it's the former, maybe a double D segment? If the latter, I personally think you'd be on the right track. Just make sure you're allowed to supply the lens in the right material. Good luck!
12-01-2020, 10:45 AM
Don Gilman

Quote:

Originally Posted by Beeped

Has he had bifocals before? I think Hoya does 'invisible' round seg bifocals in poly, not sure about trivex. With a Franklin split you'd be able to achieve a lot more peripheral, if he can get used to the image jump. Does he do both welding overhead and below? Or just in front of him, say at reading distance/position? If it's the former, maybe a double D segment? If the latter, I personally think you'd be on the right track. Just make sure you're allowed to supply the lens in the right material. Good luck!

Old school rule of thumb for image jump: Plus in distance use round seg, minus use flat top
12-01-2020, 12:21 PM
iLeeam

Quote:

Originally Posted by Beeped

Has he had bifocals before? I think Hoya does 'invisible' round seg bifocals in poly, not sure about trivex. With a Franklin split you'd be able to achieve a lot more peripheral, if he can get used to the image jump. Does he do both welding overhead and below? Or just in front of him, say at reading distance/position? If it's the former, maybe a double D segment? If the latter, I personally think you'd be on the right track. Just make sure you're allowed to supply the lens in the right material. Good luck!

He hasn't worn before, he's currently placed an order for a clear pair of varis to use day-to-day and is open to the idea of wearing those all the time. The reason he doesn't want them in his work pair is because he wants the lines to be as straight as possible and to not distort, hence the reason for advising a bif. I've been looking at Uvex as i've used them before but open to the idea of others. I did toy with the idea of a DD bif (or double round as above 'rule of thumb') so I must ask him if he needs it close up. Also, not sure if safety spec-providers will have those as an option.