Which of the following is a correct statement?

Options

A. Blind spot contains rods and cones in equal number
B. Cavity of vitreous humour lies between choroid and retina
C. Corneal grafts are not rejected because cornea is not vascularised
D. Blind spot is the degenerate zone of eye of persons who are genetically colour blind

Answer

To determine which of the statements is correct, we will analyze each option one by one.

1. **First Statement**: "The blind spot contains rods and cones in equal number."
- The blind spot, also known as the optic disc, is the area of the retina where the optic nerve exits the eye. This area does not contain any photoreceptors (rods or cones). Therefore, this statement is incorrect.

2. **Second Statement**: "The cavity of the vitreous humor lies between choroid and retina."
- The vitreous humor is the gel-like substance that fills the space between the lens and the retina. It lies behind the lens and in front of the retina, not between the choroid and retina. Thus, this statement is also incorrect.

3. **Third Statement**: "Corneal grafts are not rejected because the cornea is not vascularized."
- The cornea is avascular, meaning it does not contain blood vessels. This lack of vascularization helps in reducing the chances of rejection during corneal transplants (grafts). Therefore, this statement is correct.

4. **Fourth Statement**: "Blind spot is the degenerate zone of the eye of a person who is genetically color blind."
- The blind spot is not related to color blindness. It is simply the area where the optic nerve leaves the eye and does not have photoreceptors. Therefore, this statement is incorrect.

**Conclusion**: The correct statement among the options provided is the third statement: "Corneal grafts are not rejected because the cornea is not vascularized."