Electrochromic element, and lens unit and imaging apparatus including the same

A method of assembling an electrochromic element comprising:

• providing a pair of electrodes;
• and
• providing an electrochromic layer disposed between the pair of electrodes, a shape of a light modulating region viewed from a normal direction of the electrode being circular,
• wherein the pair of electrodes and the electronic layer are selected such that, when a sheet resistance of the electrode is rs (Ω), a resistance of the electrode is r (Ω), a diameter of the light modulating region is L (m), a distance between the pair of electrodes is d (m), the resistivity of the electrochromic layer is ρ (Ωm), and a resistance of the electrochromic layer is R (Ω), a resistance ratio (r/R) between the electrode and the electrochromic layer, as shown in equation (1), is 2 or more and 20 or less:
• r
• /
• R
• =
• (
• r
• s
• ⁢
• L
• 2
• )
• /
• (
• ρ
• ⁢
• d
• )
• .
• (
• 1
• )