Disigning the Impression Ergo FS near vision lens

[Nikolay Angelov]

Some of us have always wanted a lens we can design ourselves for each client. Now we have it, so lets share experience.
Rodenstock's Impression Ergo FS .

We have done variations of the 3 basic designs to fit them better to the client's environment.
But we are yet to do truly special designs for Surgeons, auto mechanics etc.

What is your experience?

[Craig]

Tell us the choices, it is noy in US to my knowledge.

[Nikolay Angelov]

The Impression Ergo FS is a individual near vision lens.

It is the top of the line of the Ergo series by Rodenstock.

It is optimized to the clients individual parameters:

1. frame size and shape
2. pantoscopic angle
3. face form angle (bow angle)
4. corneal vertex distance
5. interpupilary distance
6. pupil height
7. refraction data
8. near refraction distance
9. custom inset
10. custom base curve

You can select 3 basic designs: Book, PC and Room:




Up to here all the features are present in the "Impression Ergo" as well.

The Ergo FS, lens takes all this and goes further.

The "near" environment of every person is unique.
The ergonomic of his occupation and environment is different (computer user, receptionist, surgeon, dentist, hair dresser, mechanic, lecturer etc.).

So for a person to get great vision and comfort you have to tailor the lens not only to his frame and face, but to the ergonomics of his occupations and environment.

Say he is using a PC.

1. At what distance is the screen?
2. What size is it?
3. At what height is it (gaze angle)?

With this data can you calculate the prefect lens, that requires no head movement and hunting for the right zone by head movement (clear vision and comfort).

What about a surgeon?

1. His "near" environment is unique.
2. The gaze angles are noting like on a computer desk.
3. The distance when looking downwards is not 40 centimeters.
4. He has to monitor screens at 2 meters as well.
5. ...

Until now it was impossible to offer solutions to clients like them.

So here is how the Ergo FS is tailored to the environment:

You have 2 reference points near and intermediate which you can move up and down with reference to the pupil (0,1mm step). That way you can fine tune the required gaze directions.

The lens has 3 vertical zones "room" "intermediate" and "near".

You can specify the distance of clear vision you require for each of the zones in centimeters.

You can change the design by 3 design parameters. In general terms the rate of degression of the 3 zones is modified and that way you control the zone width and vision dept of field as well as how the aberrations are distributed.

We do the design work on Rodenstock's ImpressionIST video centration system, which calculates the resulting vision zones in real time.



That way the design work is easier and the client can see exactly how he will see with the lens.