Here are a few descriptions for the WordPress post tag “夜視力” (Yèshìlì, Night Vision) in Traditional Chinese, catering to different needs:

**Option 1: Short & Sweet (Best for general use):**

> 夜視力，指在昏暗環境下觀察的能力。
>
> *Translation: Night vision, referring to the ability to see in dimly lit environments.*

**Option 2: Slightly More Descriptive (Provides context):**

> 夜視力，是描述在低光照條件下（如夜晚或昏暗房間）的視覺能力。此標籤適用於相關文章，包括生物夜視、夜間攝影、以及任何與夜視相關的討論。
>
> *Translation: Night vision, describes the ability to see in low-light conditions (like nighttime or a dim room). This tag is used for relevant articles, including biological night vision, night photography, and any discussions related to night vision.*

**Option 3: Focusing on practical topics (If the blog post relates to this):**

> 夜視力，探討如何在夜晚或昏暗環境中提高視覺能力，包括生物學、技術應用、以及輔助工具等等。
>
> *Translation: Night vision, exploring how to enhance visual capabilities in nighttime or dim environments, including biology, technological applications, and assistive tools, etc.*

**Option 4: Informative and a little technical:**

> 夜視力，指弱光環境下的視覺能力，涉及視網膜、感光細胞、以及其他生理機制。 包含討論人類、動物的自然夜視能力，以及人造夜視技術，如夜視鏡等。
>
> *Translation: Night vision, refers to visual ability in dim-light environments, involving the retina, photoreceptor cells, and other physiological mechanisms. Includes discussions on human and animal natural night vision abilities, as well as artificial night vision technologies, such as night vision goggles, etc.*

**Key considerations when choosing:**

* **Target audience:** Who is your blog for? Casual readers or more technical users?
* **Blog content:** What kind of posts will use this tag? This should guide the focus of the description.
* **Keyword Optimization (SEO):** Consider adding relevant keywords (like “夜間攝影” – night photography, “夜視鏡” – night vision goggles, etc.) in your description to improve search engine visibility. If applicable, you can add these to the end of any option above.

Choose the description that best suits your needs and the overall style of your blog. I would suggest the short and sweet option for general-purpose use, if there is no other specific context to give the tag a specific focus.