![[Typical Human Eye .excalidraw.svg]] %%[[Typical Human Eye .excalidraw.md|🖋 Edit in Excalidraw]]%% In the [[Fovea]] where the [[Retina]] acts as a [[Concave Mirror]], [[Visible Spectrum|Visible Light]] will hit [[Eye Rod Cell|Rod Cells]] or [[Eye Cone Cell|Cone Cells]]. There are about 120 million rod cells, these are sensitive to light in the visible spectrum but gives little to no [[Color]] information. There 6-7 million cone cells, these are less sensitive but each of the 3 types of cone cells are specifically sensitive to either red, green, or blue light. ![[Pasted image 20251110135013.png|700]] 64% of the cones are red, 32% of the cones are green, and 2% of the cones are blue. The majority of red and green cones line directly in the [[Fovea]]. ### Far and Near Sightedness There are two [[Focal Point|focus points]] for the eye. The far point is the point is the length until incoming rays are considered [[Quasi-Parallel]] (this is $\approx +\infty$). The near [[Point|point]] is how far apart in angle rays can be to be able to still hit the same point ($\approx 25 \pu{ cm }$). This explains [[Hyperopia|Far Sightedness]] where the near point is greater than $25\pu{ cm }$ (the eye is shorter than it should be). Near sightedness ([[Myopic]]) occurs when the far point is significantly less than $+\infty$, this is caused when the eyeball is too long or if there is too much curvature in the [[Cornea]].