Optical imaging lens

An optical imaging lens, comprising a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, a sixth lens element, a seventh lens element, and an eighth lens element sequentially arranged along an optical axis from an object side to an image side, each of the first lens element to the eighth lens element comprising an object-side surface facing toward the object side and allowing imaging rays to pass through and an image-side surface facing toward the image side and allowing the imaging rays to pass through, wherein:

• a periphery region of the image-side surface of the first lens element is concave;
• an optical axis region of the image-side surface of the second lens element is concave;
• the sixth lens element has negative refracting power;
• an optical axis region of the image-side surface of the seventh lens element is concave;
• the eighth lens element has negative refracting power, and a periphery region of the object-side surface of the eighth lens element is concave;
• and
• the lens elements of the optical imaging lens are only the eight lens elements describe above;
• wherein the optical imaging lens satisfies:
• EFL/(G45+T5)≤8.500 and (T4+T6)/G45≤6.000, wherein EFL is an effective focal length of the optical imaging lens, G45 is an air gap from the fourth lens element to the fifth lens element along the optical axis, T4 is a thickness of the fourth lens element along the optical axis, T5 is a thickness of the fifth lens element along the optical axis, and T6 is a thickness of the sixth lens element along the optical axis,
• wherein when a surface of the lens element has at least one transition point, a region of the surface from a central point to a nearest transition point is defined as the optical axis region, and a region located radially outside of a farthest transition point from the optical axis to an optical boundary of the surface is defined as the periphery region, where a tangent to the at least one transition point is perpendicular to the optical axis, the central point is a point of intersection of the surface and the optical axis, and the optical boundary is defined as a point at which a radially outermost marginal ray passing through the surface intersects the surface of the lens element,
• wherein when the surface of the lens element has no transition point, the optical axis region is defined as a region of 0%-50% of a distance between the optical axis and the optical boundary of the surface, and the periphery region is defined as a region of 50%-100% of the distance between the optical axis and the optical boundary of the surface.

An optical imaging lens, comprising a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, a sixth lens element, a seventh lens element, and an eighth lens element sequentially arranged along an optical axis from an object side to an image side, each of the first lens element to the eighth lens element comprising an object-side surface facing toward the object side and allowing imaging rays to pass through and an image-side surface facing toward the image side and allowing the imaging rays to pass through, wherein:

• the first lens element has positive refracting power;
• an optical axis region of the image-side surface of the sixth lens element is concave;
• an optical axis region of the image-side surface of the seventh lens element is concave;
• and
• the lens elements of the optical imaging lens are only the eight lens elements describe above;
• wherein the optical imaging lens satisfies:
• (T1+T2+T4)/(T5+T6)≥2.000 and EFL/(G45+T5)≤8.500, wherein T1 is a thickness of the first lens element along the optical axis, T2 is a thickness of the second lens element along the optical axis, T4 is a thickness of the fourth lens element along the optical axis, T5 is a thickness of the fifth lens element along the optical axis, T6 is a thickness of the sixth lens element along the optical axis, EFL is an effective focal length of the optical imaging lens, and G45 is an air gap from the fourth lens element to the fifth lens element along the optical axis.