An eyelash tint (lash tint) is a beauty treatment that uses a semi-permanent dye to darken your natural eyelashes, making them look more defined without mascara. 

Key facts:

• Makes lashes appear darker and more noticeable. 
• Does not add length, curl, or volume. 
• Typically lasts about 4 to 8 weeks, depending on your lash growth cycle.
• The treatment usually takes around 15 to 30 minutes. 
• A patch test may be recommended, especially if you have sensitive skin or eyes.