Mirrors and lens

Plane mirrors $$x_2=-x_1$$ $$\beta=1$$

$$\frac{1}{x_2}-\frac{1}{x_1}=\frac{1}{f}$$

$$\frac{1}{f}=(n_{21}-1)\left (\frac{1}{R_1}-\frac{1}{R_2} \right )$$

$$C=\frac{1}{f}$$ - lens strength in diopters

The focal distance of a lens submerged in a different medium

$$f_2=f_1\frac{\frac{n_{lentila}}{n_2}-1}{\frac{n_{lentila}}{n_1}-1}$$

Liniar transvers magnification for lenses $$\beta=\frac{x_1}{x_2}$$

Optical systems

$$C=C_1+C_2$$

$$\beta=\beta_1*\beta_2$$

Afocal system $$\beta=-\frac{f_1}{f_2}$$

Best eyesight distance $$25 cm - 15 m$$