visualacuity 0.1.0a2

License

This software is available under the GNU General Public License v3.0. See the LICENSE file for more info.

How it works

Much of the behavior for visualacuity is documented in the following spreadsheets, (which are also used for testing the software):

• testing/test_cases_conversions.tsv demonstrates how the various methods of visual acuity measurements are converted into Snellen equivalents and LogMAR values.
• testing/test_cases_parsing.tsv expresses the rules and limitations of converting plain-text values into structured objects

Installation

pip install visualacuity

Example Usage

import visualacuity
from visualacuity import *

#############
# Basic usage
parsed = visualacuity.parse_visit({
    "Left Eye Distance SC": "20/30 -1",
    "Right Eye Near CC": "J5",
})

assert parsed == {
    "Left Eye Distance SC": VisitNote(
        text="20/30 -1",
        extracted_value="20/30",
        plus_letters=[-1],
        laterality=OS,
        distance_of_measurement=DISTANCE,
        correction=SC,
        method=SNELLEN,
        snellen_equivalent=(20, 30),
        log_mar_base=0.17609125905568127,
        log_mar_base_plus_letters=0.20107900637734125
    ),
    "Right Eye Near CC": VisitNote(
        text="J5",
        extracted_value="J5",
        laterality=OD,
        distance_of_measurement=NEAR,
        correction=CC,
        method=JAEGER,
        snellen_equivalent=(20, 40),
        log_mar_base=0.3010299956639812,
        log_mar_base_plus_letters=0.3010299956639812,
    ),
}

###########################
# "Plus" columns are merged

visit_data = {
    "Both Eyes Near CC": "20/20",
    "Both Eyes Near CC Plus": "+2"
}

parsed = visualacuity.parse_visit(visit_data)

assert parsed == {
    "Both Eyes Near CC": VisitNote(
        text="20/20",
        text_plus="+2",
        laterality=OU,
        distance_of_measurement=NEAR,
        correction=CC,
        method=SNELLEN,
        plus_letters=[+2],
        extracted_value="20/20",
        snellen_equivalent=(20, 20),
        log_mar_base=0.0,
        log_mar_base_plus_letters=-0.041646245536099975
    )
}