Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Blocking rates needed to suppress ambient light across different environments.
| Light Environment | Primary Light Sources | Blocking Rate Required |
|---|---|---|
| Dark Room (Inside) | Power supply indicators | <OD4 |
| Low Light Room (Inside) | Computer screen, emergency escape light | OD7 |
| Night Time (Outside) | Moonlight, city lights | OD9 |
| Room Light (Inside) | LED or fluorescent light | OD11 |
| Daytime Shade (Outside) | Sunlight | OD13 |
| Indirect Sunlight (Outside) | Sunlight | OD14 |
| Direct Sunlight (Outside) | Sunlight | >OD15 |
