Retina

RETINA
1. Retinal surface area – 266 mm2
2. Macula lutea – 5.5 mm in diameter
3. Fovea centralis
– 1.85 mm in diameter
– 5 degree of visual field
4. Foveola
– 0.35 mm in diameter
– Situated 3 mm from temporal edge of optic disk to 1 mm below horizontal meridian
5. Parafoveal area – 0.5 mm in diameter.
6. Perifoveal area – 1.5 mm in diameter.
7. Ora serrata – 2.1 mm wide temporally and 0.7–0.8 mm wide nasally.
8. Number of rods about – 120 million
9. Number of cones – 6.5 million
10. Highest density of cones at fovea – 199000 cones/mm2
11. Each rod – 40–60 μm long.
12. Each cone – 40–80 μm long.
13. Foveal avascular zone – 500 μm in diameter.
14. Optic disk – 1.5 mm in
diameter
15. Length of optic nerve – 47–50 mm
Intraocular – 1 mm
Intraorbital – 30 mm
Intracanalicular – 6–9 mm
Intracranial – 10 mm