Physics-Guided Optics & Ophthalmology Lab

Optics & Vision Lab

Analyze lens focal lengths, convert clinical visual acuity fractions, compute prism deviations, simulate color temperatures, and evaluate light bulb efficacy.

Luminous Efficacy Calculator

Calculate efficacy in lumens per watt, evaluate electrical efficiency relative to theoretical maximums, and compare light bulb technologies.

Light Source Metrics
lm
Total amount of light visible to the human eye.
W
Power consumed in watts.
Vintage Edison Carbon Filaments2 – 4 lm/W
Extremely inefficient. Almost all energy is radiated as thermal heat.
Standard Incandescent Bulb (60W)10 – 16 lm/W
Low efficiency. Phased out globally. 95% energy lost as heat.
Halogen Spotlights14 – 24 lm/W
Slightly hotter filament. Modestly more efficient than standard bulbs.
Compact Fluorescent (CFL)50 – 75 lm/W
Good efficiency. Uses gas excitation. Slower start times.
Modern Retrofit LED Bulb85 – 120 lm/W
High efficiency. Modern household standard. Cold touch.
Commercial High-Efficacy LED Tubes140 – 210 lm/W
State of the art chips and optimized driver circuitry.
Sodium Vapor Street Lamps100 – 150 lm/W
High efficiency but very low color rendering index (monochromatic yellow).
Theoretical Monochromatic Max (555nm)683 lm/W
The absolute thermodynamic limit where 100% of power is converted to human-visible green.
Efficacy & Efficiency Calculations
Luminous Efficacy94.1 lm/W
Optic Efficiency Rating

13.78% of maximum physics limit (683 lm/W)

Bar scaled to 25% typical threshold (lab limit of standard white light)
Class category:

High Efficiency (Standard LED)

Environmental Profile:

Outstanding modern standard. Consumes 85% less power than equivalent incandescent bulbs.

Explore Additional Utilities

Spine width — page count + paper weight ↔ mm

Calculate spine width in millimeters from page count, paper weight (gsm or basis), and cover board thickness.

bookbinding

De Broglie wavelength — particle mass + velocity → wavelength

Calculate quantum mechanical wavelengths for matter waves under both classical and relativistic velocities.

quantum-atomic

Frequency ↔ Wavelength (Sound)

Convert between sound frequency and wavelength in air or water, considering temperature and medium sound speed variations.

unit

Nectar ↔ honey — volume reduction during curing

Calculate volume and weight reduction as bees dehydrate raw floral nectar (80% moisture) down to cured honey (18% moisture).

beekeeping

Water cement ratio ↔ compressive strength

Estimate 28-day concrete compressive strength from the water-cement (W/C) ratio using Abrams' Law, or solve for desired strengths.

masonry-concrete

Currency Converter

Convert global currencies using simulated or fetched live rates (USD, EUR, GBP, JPY, etc.).

currency

Mechanical Power (W ↔ hp)

Convert physical engine horsepower ratings, mechanical draft forces, and electric wattages.

unit

Pediatric Dosing Calculator

Estimate pediatric dosages from adult recommendations using standard pediatric clinical rules: Clark's, Young's, Webster's, Fried's, and BSA methods.

health

Beam divergence — mrad ↔ degrees ↔ spot size at distance

Calculate equivalent divergence angles and spot diameter at target plane from exit waist apertures.

optics-laser

Base64 Encoder

Encode textual strings to Base64 format, or decode Base64 back to raw text.

devtools

ISO Week Number ↔ Calendar Date

Calculate ISO 8601 week numbers, week dates, and determine start/end weekdays of any given week year.

timezone

Heat Index Feels-Like

Assess felt air heat indexes using ambient temperature and relative humidity thresholds.

unit

Dovetail angle — ratio ↔ degrees for hardwood vs softwood

Convert dovetail joint slope ratios (e.g. 1:6, 1:8) to slope angles in degrees and verify hardwood/softwood suitability.

woodworking

Compression ratio — bore + stroke + head volume

Calculate static compression ratios from cylinder bore, stroke, head chamber volume, gasket thickness, deck clearance, and dome/dish specs.

automotive

Cooling & HVAC Power (BTU/h ↔ W)

Compare heating, cooling, and air conditioning power capacities with corresponding watt ratings.

unit

Scale factor (model size ↔ real world)

Convert dimensions between model design sizes and physical real-world scale targets, including imperial/metric conversions.

unit

Ground acceleration — Gal ↔ g ↔ m/s²

Convert Peak Ground Acceleration (PGA) values among Gal, gravity fractions, and m/s².

seismology

IQ score ↔ percentile rank

Map IQ scores (with standard deviations 15 or 16) to cognitive percentile ranks, rarity indices, and standard intelligence brackets.

research

Sievert ↔ rem (Dose Equivalent)

Convert between Sieverts (Sv), rem, millisieverts (mSv), and millirem (mrem) to quantify biological effects and occupational radiation risk.

unit

Dissolved oxygen — mg/L ↔ % saturation at temperature

Convert between DO mg/L and % saturation. Analyze solubility boundaries based on water temperature and salinity.

aquaculture