# Page Not Found

The URL `kostacloud/optical-design/geometry/element-types/lens` does not exist.

You might be looking for one of these pages:
- [Lens](https://docs.kostacloud.com/kostacloud/3d-geometric-elements/lens.md)
- [Aperture](https://docs.kostacloud.com/kostacloud/3d-geometric-elements/aperture.md)
- [3D Geometric Elements](https://docs.kostacloud.com/kostacloud/3d-geometric-elements.md)
- [Optical Materials](https://docs.kostacloud.com/kostacloud/material-library/optical-materials.md)
- [Paraxial Element](https://docs.kostacloud.com/kostacloud/3d-geometric-elements/paraxial-element.md)

## How to find the correct page

1. **Browse the full index**: [/sitemap.md](https://docs.kostacloud.com/sitemap.md) - Complete documentation index
2. **View the full content**: [/llms-full.txt](https://docs.kostacloud.com/llms-full.txt) - Full content export

## Tips for requesting documentation

- For markdown responses, append `.md` to URLs (e.g., `/kostacloud/3d-geometric-elements/lens.md`)
- Use `Accept: text/markdown` header for content negotiation