The scope should be mounted as low as possible. Mounting it on the slide is the way to go. Frame mounted scopes will not be accurate when the slide, lug and rails start to wear.

The top shooters have them on the slide.  The red dot scopes have a diode that is very durable.

My frame mounted scope tube unscrewed after 9 years. My guess is they will all fail sometime anyway. I have had iron sites fall off.

Use lens tissue for glasses and scopes and use lens cleaner or you may scratch or fog the lens.

The dots on the glass of scopes are oil spots.

Keep your glass carrying case clean so you don't scratch your shooting glasses.