A contact lens is a lens placed on the cornea of the eye.
Importance of buffers in contact lens products:
Buffers: They aim to keep the pH of the solutions at values between 6.6 and 7.8 in order to maintain the lens parameters and the effectiveness of the solutions. They are made by the combination of an acid and its sodium salt (phosphate and acetate for example). Borate and citrate buffers are used.
Importance of isotonicity in contact lens products:
The solution composed by isotonic saline solution.
Isotonia is expressed by osmolarity or cryoscopic lowering
- 0.236 to 0.446 mOsmoles / l (increases during the day)
- If the osmolarity of the mixture is different from that of the tears, it causes discomfort and irritation
• Increased tear secretion
• Increase the blink frequency
- If hypotonia, entry of water to the epithelial cells, if hypertonia: inverse
- Osmolarity restored 1 or 2 minutes after instillation
Your correct answer to this question is C
Carbon dioxide concentrations in soil are higher than in the atmosphere because of respiration of the plants, their roots. Also, CO2 is inhigherr concentration because of the decomposition of organic matter. Decomposition of organic matter produce more CO2 because of increased microbial activity. CO2 concentrations can change as a result of temperature change or different soil structure. Composition of air in soil and atmosphere of CO2 is
<span>Soil Air: 0.25% Atmosphere: 0.04%.</span>
They contain high protein, starch and oil reserves that help in the early stages of growth and development in a plant.
