Analysis of the old system

REIMS can be downloaded from here (ZIP). The REIMS manual (PDF) gives a very good overview of REIMS.

Link to the info page of REIMS1

It's possible to run REIMS inside VirtualBox Windows 95 (find Windows 95 here).

Using a newer Windows might be possible as well.

To run it extract all REIMS zips into one folder, because some of the ZIPs contain the Fox Pro 2.6 support library which is required. This is also explained in the REIMS manual.

Database files from foxpro

Luckily the database extraction is pretty easy thanks to the python dbfread library.

The source code of the extractor can be found here

An overview over all DBF files from REIMS:

Important

• Glsku.dbf -- eyeglass inventory db
• Dispense.dbf -- containing a record of dispensed glasses
• Rdinv.dbf -- reader inventory db
• Rdtrak.dbf -- containing a record of dispensed readers

Unsure

• Deleted.dbf -- a file of available numbers to be reused. Created by the "Utilities" -> "Make file of available numbers" or by Export/Import -> "Import re-used numbers"
• Glnxtno.dbf -- a file containing the next serial number to be used (glasses next number)
• Rdadd.dbf -- a file for recording additions to reader inventory
• Readd.dbf -- a file with data entered to replace used numbers

Other not important stuff

• Bulog.dbf -- a log of backups – also contains the location of the clinic to appear in the window title if desired
• Notfound.dbf -- a file containing the Rx’s of unsuccessful searches
• Reimshlp.dbf -- the help file

CDX (probably not important)

• Glsku.cdx -- the accompanying index file that allows the data to be displayed in the correct order
• Rdinv.cdx -- the accompanying index
• Readd.cdx -- the accompanying index

on cdx files: https://stackoverflow.com/q/3618633/4026792

PhilScore

Philscore Breakdown (PDF)

Helpful stuff to know:

• Cylinder and axis are coupled together, axis gives rotation. If the cylinder matches but the axis is totally different, that doesn't make sense.
• You always want to match both eyes, never a single one
• The "ignore cyl and axis" function is no longer required
• A prescription can be transformed to another one. That's possible because cylinder abd sphere are coupled together.

The general process

We first filter out all glasses that wouldn't get a good Philscore anyway. For that:

EITHER

1. Match Sphere +- Tolerance and
2. Match Cyl +- Tolerance

OR

1. Create new possible Rx with SPEQ() (account for the fact that cyl+sphere can be transformed, see below)

But this is just to save computing power probably, so it can be ignored.

Then comes the important stuff:

1. Filter out bad glasses with AtoLTF() (this checks for valid axis tolerances)
2. Rank using RANK() (this gives the philscore)

AtoLTF()

It filters all glasses by valid axes. The axis tolerance for that is derived from the cylinder strength.

Input: zc (Lens cyl), zac (Lens Axis), za (desired axis)

Variables: zat (i.e. AXIS TOLERANCE). A bigger cylinder allows less tolerance for the axis, a smaller one more tolerance.

Returns: Whether the Lens axis is in range of desired axis and the tolerance

See also: This reference Point 3 or this paper

SPEQ()

Calculates different possible pairs of glasses for the desired Rx because glasses can be transformed based on sphere+cylinder.

It works because adding a value to Rx cylinder (remember cyl > 0 not possible!) and subtracting half of that value from the Rx sphere, will give you roughly the same Rx.

Input: desired Sphere, desired Cylinder (Axis not used here?)

Calculcates: An array of other possible Rx's (consisting of sphere+cylinder). First pair (cylinder+0.5, sphere-0.25), second (cylinder+1, sphere-0.5), third (cylinder+1.5, sphere-0.75)

Returns: It filters all glasses if they match to one of the newly calculcates Rx's. It's unclear how the axis is used here? I assume it again calls the AtoLTF function here

PhilScore RANK()

The actual PhilScore/Rank function which calculcates the score

Input: desired sphere, cyl and add for OS and OD, measured sphere, cyl and add for OS and OD (no axis??)

Returns an index based on a lot of conditions

For RANK() see also this source code from 5 years ago

Helpful stuff

SA and SM are the 2 sites

There is no correlation between the SKU and the power of the glasses that is assigned to it (so the SKU can be generated automatically)

Rx = Prescription = A pair of glasses descriped by its parameters like strength and others

SKU= Stock keeping unit i.e. serial number

Notes from analyzing source

• mrlb: OD;OS;Both (always 3)
• mtype: (s)ingle or (b)ifocal
• mica: Ignore cylinder and axis (always false)
• zeye: always 'OU' (both eyes)
• zods: odsphere
• zosa: osadd

Variables ending with d always OD (left eye), with s are OS

.F. is false; .T. is true

• rxs(d/s): Rx sphere

• rxc(d/s): Rx cylinder

• rxa(d/s): Rx axis

• rxad(d/s): Rx additional

• s(d/s)(1-3): spherical equivalent Sphere, pair 1,2,3

• c(d/s)(1-3): spherical equivalent Cylinder, pair 1,2,3